2,965 results on '"FERROELECTRICITY"'
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2. Improving the thermal stability of 180° domain switching by engineering the ferroelectric/electrode interface
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Jeyaseelan, Antony, Vishwanath, Sujaya Kumar, Yoon, Sukeun, and Kim, Jihoon
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- 2025
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3. Tailoring La doping concentration for superior ferroelectric and energy storage performance in Bi2WO6 thin films
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Ahn, Yoonho and Son, Jong Yeog
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- 2025
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4. Investigating the photodetection performance of self-biased Au/PZT/ FTO and Au/PZT/Au/FTO UV photodetectors
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Ashtar, M., Marwat, M.A., Bentalib, A., Jumah, A.B., Yang, Y., Xue, W., and Cao, D.
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- 2025
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5. Surface-Induced effects in ferroelectric BaTiO3 thin films
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Kushwaha, Anoop Kumar, Khadka, Rajan, and Keblinski, Pawel
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- 2025
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6. Spin-coated BiFeO3 films on Si wafers: Low processing temperature but prominent piezoelectricity
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Yi, Jiaojiao, Zhai, Yining, Cheng, Yue-yu-shan, Shu, Liang, Zhang, Dawei, Li, Jing-Feng, and Liu, Lisha
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- 2025
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7. Large ferroelectric polarization and high dielectric constant in HfO2-based thin films via Hf0.5Zr0.5O2/ZrO2 nanobilayer engineering
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Liu, Lei, Jiang, Chengfeng, Yuan, Xi, Zhang, Yan, Chen, Haiyan, and Zhang, Dou
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- 2025
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8. Esterified phenylalanine supramolecular motion: Anion order–disorder rotation induced reversible phase transition and dielectric-ferroelectric properties
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Liu, Yang, Wang, Na, Yao, Yubing, Qi, Huanhuan, Hu, Hongzhi, Zhang, Tong, and Liu, Zunqi
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- 2025
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9. Heteroepitaxial growth of PMN-PT thin films on SrTiO3 buffered III-V semiconductor GaAs by pulsed laser deposition
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Du, Xiaona and Ning, Xin
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- 2025
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10. Rapid microwave annealing of ferroelectric copolymer films for multifunctional perception
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Luo, Xingsheng, Yang, Jiang, Feng, Yirou, and Zhu, Guodong
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- 2024
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11. Ferroelectricity and nanotube-induced synthesis of one-dimensional group-Ⅳ monochalcogenide nanowires
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Guo, Jiasen, Li, Xinxin, Wang, Huijuan, Zhong, Chenghuan, Zheng, Xiaole, Chen, Ying, Yang, Dingyan, Xie, Shimao, and Li, Chunmei
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- 2023
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12. First-principles study of polar magnets corundum double-oxides Mn2FeMO6 (M = W and Mo)
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Ali, Akbar, Elsaeedy, H.I., Ullah, Sami, Ali Khan, Sayed, and Khan, Imad
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- 2022
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13. Temperature dependent dielectric and ferroelectric properties of Sr2Na(1-x)K(x)Nb5O15 (0≤x≤0.07) Tetragonal Tungsten Bronze (TTB) ceramics.
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Riaz, Muhammad Fahad, Hussain, Fayaz, and Chandio, Ali Dad
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ENERGY density , *PERMITTIVITY , *DIELECTRIC properties , *TUNGSTEN bronze , *POWER capacitors , *CERAMICS - Abstract
Relaxor ferroelectric (RFE) materials show potential candidat for many everyday applications due to their stabilized crystal structure, also appealing for energy storage, and pulse power capacitors because of their highly unique characteristics. In the present work, Sr 2 Na (1- x) K (x) Nb 5 O 15 (SNKN) ceramics with (x = 0.00–0.07) were synthesized using commercial grade raw materials through solid state processing technique. The effect of K+ doping in the A site on crystal structure, relaxor behavior, and energy storage characteristics was analyzed. All the compositions show P 4 bm space group with single phase tetragonal structure. The dielectric property reveals that all ceramics compositions have low losses (tan δ < 5 %) at RT and further losses reduce at higher temperatures. The composition with x = 0.03, the maximum permittivity achieved is (ε m = 2338). Moreover, an analysis on the energy storage density and efficiency of K+ content was carried out. At an applied electric field of 40 kV/cm, SNKN ceramics with x = 0.07, energy storage density (W rec = 0.35 J cm−3) and efficiency (η = 82 %) was optimized. The variation in W rec from RT to 120 °C is very small and efficiency (η) was remained above 88 %. Nevertheless, the response of energy storage of these formulations is low, but they are new class of materials demonstrating better relative permittivity, lower tan δ, and temperature stability in Ferroelectricity and representing potential applications at high temperatures. [ABSTRACT FROM AUTHOR]
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- 2025
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14. Evidence of multiferroic behavior in sintered BaTiO3 obtained from high-energy ball-milled powders.
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Reséndiz-Trejo, Y., Sánchez-De Jesús, F., Betancourt-Cantera, L.G., Reyes-Valderrama, M.I., Cortés-Escobedo, C.A., and Bolarín-Miró, A.M.
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MULTIFERROIC materials , *DIELECTRIC materials , *FERROELECTRIC materials , *PERMITTIVITY , *DIFFRACTION patterns - Abstract
Multiferroic BaTiO 3 exhibiting ferroelectric and ferromagnetic behavior was synthesized via the high-energy ball milling of pure BaTiO 3 (BTO) powders for durations ranging from 15 to 60 min, followed by pressing and sintering at 1200 °C X-ray diffraction patterns of all synthesized samples predominantly revealed a BTO phase with a tetragonal structure and a secondary Ba 12 Fe 28 Ti 15 O 84 (BFTO) phase. The BFTO phase was formed after milling for more than 30 min because of chemical interactions between the BTO powder and milling media. Vibrating sample magnetometry confirmed the ferromagnetic nature of the sintered pellets. The specific magnetization increased with increasing milling duration, reaching a maximum value of 1.15 emu/g after 60 min of milling. This increase can be attributed to the distortion of the crystal structure and presence of a secondary phase, as confirmed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Additionally, electrical characterization revealed the dielectric nature of the materials, with relative permittivity ranging from 500 to 1800, maximum spontaneous polarization from 9.77 to 11.31 μC/cm2, coercive field from 3.86 to 11.12 kV/cm, and AC conductivity from 1 × 10−6 to 1 × 10−3 S/cm. The method described in this study is a simple and cost-effective approach to produce multiferroic materials with ferroelectric and relaxor ferroelectric behavior at room temperature, broadening their potential for technological applications. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Ferroelectricity in Ce0.2-HfO2 films around 500 nm in thickness.
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Wu, Yida, Xu, Junbo, Bai, Mei, Kang, Ruirui, Qiao, Wenjing, Gao, Yangfei, Hu, Yanhua, Wang, Danyang, Zhao, Jiantuo, Wang, Jiping, and Lou, Xiaojie
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CHEMICAL solution deposition , *CERIUM oxides , *HAFNIUM oxide , *HYSTERESIS loop , *FERROELECTRICITY , *FERROELECTRIC thin films - Abstract
CeO 2 -HfO 2 solid solution thin films (Hf 1-x Ce x O 2) were deposited on Pt(111)/TiO 2 /SiO 2 /Si(100) substrates using the chemical solution deposition method. This study investigates the influence of CeO 2 content and annealing temperature on the structure and ferroelectric properties of Hf 1-x Ce x O 2 films. Ferroelectric behavior is demonstrated in polycrystalline Hf 0.80 Ce 0.20 O 2 films with thicknesses ranging from 163 to 524 nm. And the structure of the films is analyzed using glancing incidence X-ray diffraction. The comprehensive results indicate that Hf 0.80 Ce 0.20 O 2 films annealed at 850 °C exhibit excellent ferroelectricity. Square hysteresis loops associated with the ferroelectric orthorhombic phase are observed, even in the 524-nm-thick film. The remnant polarization (P r) and coercive field (E c) range from 16 to 18 μC/cm2 and 1100–1250 kV/cm, respectively, under a maximum applied electric field of 2 MV/cm for all Hf 0.80 Ce 0.20 O 2 films. Furthermore, the film presents thickness-insensitive characteristic. The current work paves the new way to design high-performance thick HfO 2 -based ferroelectric films. [ABSTRACT FROM AUTHOR]
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- 2024
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16. Improved ferroelectricity and endurance in Ca doped Hf0.5Zr0.5O2 films.
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Yin, Lu, Li, Xinyu, Xiao, Duoduo, He, Sijia, Zhao, Ying, Peng, Qiangxiang, Yang, Qiong, Liu, Yunya, and Wang, Chuanbin
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CHEMICAL solution deposition , *STRAY currents , *HAFNIUM oxide , *SURFACE roughness , *FERROELECTRICITY - Abstract
Doped Hf 0.5 Zr 0.5 O 2 materials have drawn increasing attention due to the excellent ferroelectric properties, but the relevant research is just in the preliminary stage and the reported doped systems are rare. In this work, Ca doped Hf 0.5 Zr 0.5 O 2 (Ca:HZO) ferroelectric films were successfully fabricated via chemical solution deposition and investigated for the first time. It is observed that Ca doping induces a phase transformation from monoclinic to orthorhombic/tetragonal and then to monoclinic/tetragonal. The highest orthorhombic phase fraction is achieved in 2.5 mol% Ca doped HZO film, contributing to the optimum ferroelectric property with the largest remnant polarization of 14.00 μC/cm2 after 105 cycles. Additionally, the leakage current density is observed to decrease with increasing Ca content, which is mainly associated with the changes of grain size and surface roughness. As a result, the endurance is significantly improved in the Ca doped films, and an excellent endurance of 1010 cycles is achieved in the 2.5 mol% Ca doped film. These results suggest that Ca doping can enhance the ferroelectric and endurance properties of HZO films by optimizing the phase and morphological structure. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Unveiling the structural, optical, electrical, and ferromagnetic properties of Ca2+ doped mixed spinel ferrites for switching field high-frequency device applications.
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Jain, Prachi, Shankar, S., and Thakur, O.P.
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FIELD emission electron microscopy , *SIZE reduction of materials , *MICROWAVE devices , *UNIT cell , *X-ray diffraction - Abstract
In this paper, the calcium-doped nickel-zinc nano-ferrites [Ni 0.5 Zn 0.5 Ca x Fe 2-x O 4 ; x = 0.00, 0.10, and 0.30] were prepared using the chemical co-precipitation synthesis route and studied for switching field high-frequency device applications. The structural analysis has been completed by analyzing X-ray diffraction (XRD) patterns. The Rietveld refined XRD patterns confirmed the formation of cubic spinel structure of Ca2+ substituted nickel-zinc ferrites. The detection of metal-oxygen bonds present at A and B lattice sites has been unveiled by Fourier transform infrared (FTIR) spectroscopy. The morphological studies obtained through FESEM (Field emission scanning electron microscopy) analysis showed a reduction in the particle size from 70 nm to 53 nm when the concentration of Ca2+ ions in Ni-Zn ferrites was increased. Energy dispersive spectra (EDS) confirmed the presence of elements present in the prepared composition. The structure of a cubic spinel-shaped unit cell has been verified from three active prominent Raman modes (A 1g , A 2g , and T 2g). Diffuse-reflectance spectroscopy (DRS) exhibits the increment in the bandgap values (from 1.55 eV to 1.63 eV) which helps fabricate highly efficient photovoltaic devices. The ferroelectric measurements yielded a rise in polarization values from 1.461 μC/cm2 to 18.228 μC/cm2 for 10 % Ca2+ ion substitution. The tangent loss values declined from 24 to 3 in Ni-Zn ferrites upon substituting Ca2+ ions. The Vibrating sample Magnetometer (VSM) technique found the increment in the saturation magnetization (M s) values from 34.724 emu/g to 54.662 emu/g on substituting up to 30 % Ca2+ ions in Ni-Zn ferrites. These obtained results support the material in switching field distribution for high-frequency applications. The results exhibited that the prepared samples can be applicable for switching devices, filters, and microwave absorption devices. The results revealed the maximum frequency between 12 and 18 GHz which is useful for Ku band absorption. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Transverse size effect of relaxor ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 film for one- and two-dimensional integrated sensors by simulation.
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Liang, Cao, Gong, Zhentao, Wang, Simin, Wei, Mianhao, Zhang, Qiaozhen, Duan, Zhihua, Wang, Tao, Tang, Yanxue, Zhao, Xiangyong, and Wang, Feifei
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PYROELECTRIC detectors , *PERMITTIVITY , *THIN films analysis , *FERROELECTRICITY , *SENSOR arrays - Abstract
In this work, the transverse size effect of the new-generation relaxor ferroelectric Pb(In 1/2 Nb 1/2)O 3 -Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 (PIMNT) thin film was studied by finite element method, aiming to revealing the lateral size and shape dependence of the piezoelectric, dielectric, and pyroelectric behavior for guiding one- and two-dimensional integrated array sensor applications. The results indicated that as the aspect ratio (width to thickness ratio) decreased from 100 to 0.01, for both one-dimensional rectangular and two-dimensional square PIMNT array elements, a sharp increase in piezoelectric and dielectric constants could be observed for the PIMNT with <001> direction while a slight increase could be found for those along <111> orientation, exhibiting a strong orientation dependence. In comparison, the PIMNT with <110> direction exhibited strong shape dependence. The piezoelectric and dielectric constants of <110>-oriented square element increased more remarkably than those of the rectangular one. The pyroelectric coefficients of PIMNT exhibited weak shape dependence, decreasing from 8.5 × 10−4 C/(m2·K) to about 8.0 × 10−4 C/(m2·K) for both element shapes with transverse size decreasing. These findings give insight into the transverse size and shape effect on the new-generation PIMNT thin film and provide a guide for its design in one- and two-dimensional piezoelectric and pyroelectric array sensor applications. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Chemically driven BaTiO3–CoFe2O4 nanocomposite with strong dielectric and low leakagecharacteristics for electrocatalytic water splitting reaction.
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Singh, Purnima, Mahato, Anupama, Mondal, Debasish, Panda, Bholanath, Sahis, Amrit, Pramanik, Anup, and Dhak, Debasis
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TEMPERATURE coefficient of electric resistance , *HYDROGEN evolution reactions , *PERMITTIVITY , *STRAY currents , *FERROELECTRICITY , *OXYGEN evolution reactions - Abstract
The switchable electronic properties at the surface of ferroelectric nanomaterials offer possibilities for electrocatalytic hydrogen and oxygen evolution reactions, HER and OER respectively. Here, 0.5(BaTiO 3)-0.5(CoFe 2 O 4) (abbreviated as BTCF0.5) are prepared chemically. The material shows a high dielectric constant in the order of 107. Nyquist plot is consistent with non-Debye-type and negative temperature coefficient of resistance (NTCR) characteristics with low leakage current. BTCF0.5 shows superior electrocatalytic HER and OER with a low overpotential of ∼156 and ∼284 mV at current density10 mA/cm2 along with Tafel slopes of 43.37 mV/dec and 41.52 mV/dec respectively. The stability of the electrocatalyst is checked through a chronoamperometry test and up to 1000 cycles of CV both for HER and OER operations. The non-traditional behavior of the nanocomposite may make it highly desirable for usage in numerous renewable and sustainable energy-related applications in the present-day scenario. [Display omitted] • 0.5BaTiO 3 -0.5CoFe 2 O 4 nanocomposite sample was synthesized by chemical route. • A high dielectric constant in the order of 104 - 107 was observed at room temperature. • An impedance study was performed which confirmed the non-Debye type relaxation. • HER, OER showed 156 mV and 284 mV overpotential at 10 mA cm−2 current density. • The electrocatalyst showed ∼1.65 V cell voltage for overall water splitting. [ABSTRACT FROM AUTHOR]
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- 2024
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20. Magnetic and dielectric properties of the new YFeO3/BiFeO3 nanocomposite ceramics prepared via reverse chemical co-precipitation followed by spark plasma sintering.
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Sangian, H., Mirzaee, O., and Tajally, M.
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FERROELECTRICITY , *MAGNETIC measurements , *DIELECTRIC properties , *BISMUTH iron oxide , *TRANSMISSION electron microscopy - Abstract
New xYFeO 3 – (1-x) BiFeO 3 (0.0 ≤ x ≤ 1.0) multiferroic composites were prepared successfully via the chemical co-precipitation followed by high energy mechanical blending. For the structural analysis, assessment of phase purity, and characterization of oxidation states, XRD, FTIR and XPS methods were utilized, respectively. Furthermore, morphological investigations and elemental distribution within the composite samples were elucidated through FESEM and TEM imaging techniques. The VSM results indicated that the values of M s and M r increase alternately from 0.553emu/g and 0.049emu/g to 1.210emu/g and 0.166emu/g, respectively, with an increase in the YFO content from 20 % to 80 %. These values of M s do not follow a linear combination of the base phases, and the magnetization of each composite sample is accompanied by an additional value. This additional value may arise from the residual strain and interfacial magnetic and electrical interactions between the parent phases. The measurements of dielectric properties disclosed that the behavior of the samples follows the Maxwell-Wagner polarization. Moreover, the values of ε′ at the frequency of 200 Hz increased from 149 to 303 as the BFO content rose from 20 % to 80 %. In addition, the lowest recorded tanδ value was 0.56 for the 6Y4B sample at 200 Hz. Furthermore, the conductivity measurements showed that the behavior of all samples follows Johnscher's power law. • The phase-pure YFeO 3 /BiFeO 3 nanocomposites with well-dispersed particles were synthesized using the reverse co-precipitation. • The magnetostriction effect in BFO and the ferroelectric properties of YFO altered the overall magnetization in the system. • The significant enhancement of the coercive field relative to the original phases was emphasized in all composite samples. • The rise in the YFO content in the composite specimens led to a drop in the dielectric constant. [ABSTRACT FROM AUTHOR]
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- 2024
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21. Influence of annealing atmosphere on polarization behaviors of Hf0.5Zr0.5O2 ferroelectric films deposited on Ti electrodes.
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Chen, Haiyan, Jiang, Chengfeng, Chen, Ying, Liu, Lei, Yan, Zhongna, Li, Chuanchang, and Zhang, Dou
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DENSITY functional theory , *STRAY currents , *FERROELECTRICITY , *THIN films , *GRAIN size , *FERROELECTRIC thin films - Abstract
Ferroelectric properties of HfO 2 -based films are reported to be largely influenced by various factors including stress, grain size and oxygen vacancies. In this study, Hf 0.5 Zr 0.5 O 2 (HZO) films were deposited directly on Ti bottom electrode (Ti-BEs). The polarization switching behavior and fatigue performance exhibited notable distinctions as a result of varying oxygen vacancies in the films upon annealing under different atmosphere of N 2 , air and O 2 with different annealing time. The HZO film after being annealed in air demonstrated a comparatively larger remnant polarization (P r) value of 20.4 μC/cm2 and superior fatigue performance over 108 field cycles. Furthermore, the internal mechanisms were analyzed through density functional theory (DFT) calculations. The introduction of more oxygen vacancies was observed to reduce the formation energy of o -phase and promote the enhancement of ferroelectricity. However, it should be noted that this also resulted in an increase of leakage current. Therefore, it is crucial to carefully control the concentration of oxygen vacancies, considering the overall impact on both the reliability and ferroelectricity of thin films. The results of this work can provide an effective pathway to grow HZO ferroelectric films with high performance through the control of oxygen vacancies concentration. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Significant enhancement of ferroelectric performance in lead-free NaNbO3 ceramics.
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Li, Zekun, Xun, Wenhao, Huang, Xiaohua, Wan, Youhe, Liu, Yaochen, Gu, Siyu, He, Wenbo, Yang, Weixue, Lin, Zhiming, Wang, Baoyuan, and Hou, Ying
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FERROELECTRIC materials , *ENERGY storage , *FERROELECTRICITY , *ELECTRIC fields , *ENERGY futures , *CERAMICS , *LEAD-free ceramics - Abstract
The comparable free energy between antiferroelectric (AFE) and ferroelectric (FE) phases in NaNbO 3 (NN) leads to unstable ferroelectricity, restricting future applications for energy storage devices. In this work, lead-free NN ceramics based on different sintering aids have been rigorously synthesized and the microstructural, dielectric, and ferroelectric properties of this system have been thoroughly examined. It is found that a tiny amount of sintering aids effectively lowers the sintering temperature and manipulates the grain growth, as well as plays an essential role in the stability of FE phase in NN ceramics. The tunable ferroelectricity is observed in NN: CuO as sintering aids results in a hardening effect, whereas MnO 2 addition promotes softening behavior. More interestingly, introducing 1 wt% MnO 2 as sintering aids results in strong ferroelectricity with high polarization (P m) of 84.6 μC/cm2 stabilized by a stimulated electric field (E f) as low as 60 kV/cm. This is significantly better than other NN-based ceramics (P m is smaller than 40 μC/cm2 and E f is higher than 90 kV/cm in the NN-based systems reported earlier). Our findings demonstrate the potential of sintering aids in tailoring the ferroelectric performance of lead-free NN ceramics, offering insights into the development of environmentally friendly ferroelectric materials. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Structural and electrical properties of tetragonal tungsten bronze K4Bi2Nb10O30-Ba4Na2Nb10O30 solid solutions across two proximate phase transitions.
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Løndal, Nora Statle, Zeiger, Caren Regine, Grendal, Ola Gjønnes, Einarsrud, Mari-Ann, Walker, Julian, and Grande, Tor
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TUNGSTEN bronze , *PHASE transitions , *SOLID solutions , *LEAD-free ceramics , *TRANSITION temperature , *FERROELECTRICITY - Abstract
Tetragonal tungsten bronzes allow for broader compositional engineering compared to perovskites. Here we investigate solid solutions between Ba 4 Na 2 Nb 10 O 30 (BNN) and K 4 Bi 2 Nb 10 O 30 (KBiN). A transition from orthorhombic to tetragonal symmetry was observed at 30–35 % KBiN. An expansion of the in-plane and a contraction of the out-of-plane parameter were observed with increasing KBiN content. Ferroelectricity, shown by a maximum in permittivity, was observed up to 20–35 % KBiN, while diffuse dielectric behaviour was exhibited from 40 % KBiN. Non-linear P-E loops are evident up to 35 % KBiN, and vaguely present for 40 % KBiN. The most prominent ferroelectric character, assigned by large remanent polarisation and opening of the strain hysteresis response was exhibited at 35 % KBiN. A ferroelastic-paraelastic phase transition between 30 % and 35 % KBiN and a ferroelectric-paraelectric phase transition around ∼40 % KBiN were inferred. Thus, the two distinct phase transitions mimic the temperature dependent structural evolution observed for BNN. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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24. Flexible epitaxial LiNbO3 thin film with ferroelectricity and nonlinear optical response.
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Tian, Hongxia, Jiang, Chengming, Alodhayb, Abdullah, Wang, Feng, and Huang, Jijie
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THIN films , *FERROELECTRICITY , *SECOND harmonic generation , *OXIDE coating , *SUBSTRATES (Materials science) , *OPTICAL devices - Abstract
Flexible or wearable devices are of great interests in the modern technologies, and oxide thin films are critical components for such applications. In this work, epitaxial LiNbO 3 (LNO) thin film integrated on flexible mica substrate has been achieved. Al-doped ZnO (AZO) layer has been first deposited as buffer layer to obtain the epitaxial LNO film, furthermore AZO serves as bottom electrode for electrical measurement. The as-deposited LNO film exhibits high epitaxial quality with c-direction growth. The transmittance measurement indicates the high transparency of the film, ~85 % in visible range and ~90 % in near infrared region up to 1500 nm. The second harmonic generation (SHG) measurement confirms the nonlinearity of the flexible LNO film. The LNO/AZO/mica film also presents apparent ferroelectric response. Overall, the high-quality LNO integrated on flexible mica could be potentially applied in wearable optical and electrical devices. [ABSTRACT FROM AUTHOR]
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- 2024
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25. Tailoring room-temperature ferroelectric, magnetic and magnetoelectric properties in La and Se co-doped BiFeO3 embedded Ti3C2Tx MXene free-standing ceramics film.
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Kindohoun, Lazare, Sattar, Kubra, Tahir, Rabia, Irfan, Syed, and Rizwan, Syed
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DOPING agents (Chemistry) , *MAGNETIC properties , *TITANIUM carbide , *HYBRID materials , *HEAT treatment , *MULTIFERROIC materials - Abstract
The ever-growing need for advancement in data storage technology demands materials that can be controlled by as many degrees as possible. In this regard, multiferroic materials that show response both in electric and magnetic dimensions are of great interest especially when being investigated in two-dimensional materials that have their potential applications. In this study, we have incorporated Lanthanum (La) doped Bismuth Ferrite (BLFO), and La and Selenium (Se) co-doped BFO (BLFSO) with two-dimensional layered titanium carbide (Ti 3 C 2 T x) from the class of MXene as hybrid composites. The structural, optical and morphological investigation validated the successful etching of MXene from MAX, successful hybrid formation with conserved crystal structure and new phases of titanium dioxide (TiO 2) detected when the samples underwent heat treatment. This heat treatment was performed in order to enhance the multiferroic properties owing to the presence of TiO 2. Our results showed that the heated BLFSO-embedded Ti 3 C 2 T x hybrid composite showed maximum remnant polarization and higher dielectric response when measured with respect to the varying electric field and at different frequencies. The prepared samples also exhibited tunable polarization response at an applied static magnetic field, unveiling their magnetoelectric properties. [ABSTRACT FROM AUTHOR]
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- 2024
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26. Ferroelectric polarization and conductance filament coupling for large window and high-reliability resistive memory and energy-efficient synaptic devices.
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Li, Ming, Zou, Zhengmiao, Xu, Zihao, Zheng, Junfeng, Li, Yushan, Tao, Ruiqiang, Fan, Zhen, Zhou, Guofu, Lu, Xubing, and Liu, Junming
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FERROELECTRIC thin films ,FERROELECTRIC capacitors ,FIBERS ,FERROELECTRICITY ,NEUROPLASTICITY ,ENERGY consumption ,OXYGEN detectors - Abstract
• High on/off ratio ferroelectric resistive memory. • Enhanced durability and retention characteristics. • Remarkably Low-energy synaptic emulation. Ferroelectric capacitors hold great promise for non-volatile memory applications. However, the challenge lies in fabricating resistive switching devices with a high on/off ratio, excellent non-volatility, and a simple manufacturing process. Here, a novel approach is introduced by demonstrating the efficacy of the coupling effect between ferroelectric polarization and oxygen vacancy-based conductive filaments in Hf 0.5 Zr 0.5 O 2 (HZO) films for the creation of non-volatile resistive switching memory devices, achieving an impressive on/off ratio of 6.8 × 10
3 at +1.8 V. An in-depth exploration of the resistive switching mechanism is provided and subsequently the outstanding durability and retention characteristics of these devices for resistive switching is validated. Furthermore, the device's capacity to emulate non-volatile synaptic functionalities is assessed. Our results reveal that under pulsed conditions of 1 V/–2 V with 1 µs pulses spaced 50 ms apart, the device can robustly achieve potentiation/depression synaptic plasticity, while exhibiting energy consumption (0.16 fJ for potentiation, 0.12 fJ for depression) reduced by 1–2 orders of magnitude compared to biological synapses. This work holds significant value as a reference for the fabrication of energy-efficient, non-volatile memory and synaptic devices. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2024
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27. Enhancement of ferroelectricity in chemical-solution-deposited ZrO2 thin films through fine phase transition control.
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Sun, Yue, Ning, Jianping, Xi, Juan, Duan, Jinqi, and Zhou, Dayu
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PHASE transitions , *FERROELECTRIC thin films , *ZIRCONIUM oxide , *THIN films , *CHEMICAL solution deposition , *FERROELECTRICITY - Abstract
Recent studies have highlighted the ferroelectric potential of ZrO 2 thin films, which offer advantages over HfO 2 -based ferroelectric materials, such as lower thermal budget and greater natural abundance. In this research, pure ZrO 2 ferroelectric thin films were fabricated on Si substrates using chemical solution deposition with all-inorganic precursors. We explored the impacts of film thickness and HfO 2 seed layers on phase transition and ferroelectric properties. Notably, an 11 nm thick ZrO 2 film exhibited ferroelectric behavior with a remanent polarization of 12.6 μC/cm2. Due to the combined effects of tensile stress and surface energy, the increase in thickness to 30 nm led to a phase transition from the orthorhombic phase to the monoclinic phase and a resultant decrease in remanent polarization. Additionally, the introduction of a HfO 2 seed layer facilitated the crystallization of the ferroelectric o-phase, enhancing the remanent polarization to 16.5 μC/cm2 in our ∼8 nm thick ZrO 2 thin film with a ∼2 nm thick HfO 2 seed layer. These findings provide valuable insights into optimizing ferroelectric properties in ZrO 2 thin films through phase transition control. [ABSTRACT FROM AUTHOR]
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- 2024
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28. Enhancing ferroelectricity in HfAlOx-based ferroelectric tunnel junctions: A comparative study of MFS and MFIS structures with ultrathin interfacial layers.
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Park, Yongjin, Park, Woohyun, and Kim, Sungjun
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TUNNEL junctions (Materials science) , *FERROELECTRIC materials , *SEMICONDUCTOR materials , *MANUFACTURING processes , *PHYSIOLOGICAL stress , *NONVOLATILE memory , *FERROELECTRICITY , *FERROELECTRIC polymers - Abstract
This study explores the potential advantages of metal–ferroelectric–insulator–semiconductor (MFIS) structures compared with established metal–ferroelectric–semiconductor (MFS) and metal–ferroelectric–metal structures in the context of nonvolatile memory devices. Despite the superior performance of MFS structures in terms of electric field maintenance, switching speed, and power consumption, the presence of interface-related issues between the ferroelectric material and the semiconductor may degrade device performance. We propose an MFIS structure incorporating ultrathin interfacial layers (ILs) of SiO 2 , HfO 2 , and ZrO 2 to address these issues. These insulator layers enhance device endurance by reducing physical stress and trap density at the interface, thereby improving electrical performance and long-term stability. Moreover, the presence of an IL reduces charge leakage between the ferroelectric layer and semiconductor, contributing to the resolution of the sneak path current problem. An additional feature of MFIS devices is their self-rectifying behavior, simplifying circuit design and manufacturing processes by eliminating the need for an external rectification circuit, consequently reducing costs. Through a series of experiments, this study evaluates the performance of the MFIS structure, investigates the ferroelectric properties of HfAlOx-based FTJs, and examines the conduction mechanism of the MFIS structure. By comparing the o-phase of MFS, SiO 2 , HfO 2 , and ZrO 2 devices via grazing incidence X-ray diffraction (GIXRD) and using the positive-up-negative-down method to extract polarization and coercive voltage, we provide a comprehensive investigation of the impact of ultrathin ILs on ferroelectric properties. This research aims to offer valuable insights into the advancement of memory device technologies, presenting the MFIS structure as a promising platform for next-generation memory technologies. Further sections will elaborate on the experimental setup, methodology, and detailed study findings. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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29. Superconductivity and interfaces.
- Author
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Maggiora, Joshua, Wang, Xiaolin, and Zheng, Rongkun
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SUPERCONDUCTIVITY , *CUPRATES , *PHENOMENOLOGICAL theory (Physics) , *FERROELECTRIC materials , *TOPOLOGICAL insulators , *TECHNOLOGICAL innovations - Abstract
The interfaces between superconductors and other materials have long been established as being an important part in the exploration of new physics to aid in our understanding of superconductivity and open us up to new technological advancements. Herein this article we analyse the recent progress made in the understanding of superconductivity at the interfaces involving a wide range of functional materials, mostly looking at two-dimensional (2D) systems. We start off in the first half of this review by focusing on magnetic and superconductive hybrid heterostructures, as well as the resulting physical phenomena from these systems. The first is a section on vortex and anti-vortex phenomena; the second key area is ferromagnet–superconductor hybrid phenomena with particular interest of magnetic skyrmions, the third is the novel frontier based on 2D magnetic and superconductive interfaces particularly examining Ising superconductivity at these interfaces; the fourth is superconductivity at anti-ferromagnetic interfaces and finally half-metals at superconducting interfaces. The second half of this review focuses on superconductivity at insulating and other functional interfaces. Examining firstly, Mott insulator interfaces with wide ranging discussions about how such interfaces can enhance our understanding in high-temperature superconductive cuprates and other unconventional superconductor systems such as the nickelates; in the second section the interface of 2D and 3D ferroelectric materials with superconductors with a key emphasis on devices that have been developed to control the superconducting phase; Topological insulators at interfaces with superconductors is the third section; and lastly 2D twisted material interfaces are explored, including the newly discovered magic angle interfaces discovered with graphene and other van Der Waals materials. It is anticipated that this review will lead to further interest in such interfaces to improve our understanding and expose the exotic science behind these interfaces. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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30. Strain-drived giant flexoelectric field and its efficient modulation in (111) BiFeO3 films.
- Author
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Zheng, Xu, Zhou, Yong, Liang, Ning, Yin, Shuaishuai, Gu, Yueliang, Zhang, Xingmin, Qiu, Zhiyong, Yang, Tieying, Wang, Can, and Li, Xiaolong
- Subjects
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SURFACE structure , *STRAINS & stresses (Mechanics) , *X-ray reflection , *FERROELECTRICITY , *ELECTRON density - Abstract
Flexoelectric effect in ferroelectric epitaxy films has attracted significant attention due to its theoretical and application potentials. However, the origin and control of flexoelectric field is not yet fully understood. In this study, we investigated the surface structure of single-domain epitaxial BiFeO 3 films with a (111) orientation using grazing incidence X-ray diffraction and X-ray reflection methods. We observed large strain gradient on the surface of the BiFeO 3 films, which produces a giant flexoelectric field up to 82.55 MV/m at the surface of 15 nm thick BiFeO 3 film. Additionally, we discovered the presence of a surface layer with lower electron density than that of the underlying BiFeO 3 layer, which is related to the flexoelectric field. Moreover, with increased film thickness, we found the strain distribution along growth direction of the film is changed, thereby leads to the decreased flexoelectric field and increasing thickness of the surface layer respectively. These findings convinced the coupling between the strain state and surface structure, changing the thickness of the ferroelectric film and consequently the strain state is an efficient way to adjust the flexoelectric field and the surface structure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Colossal permittivity and ferroelectric properties regulation of different kinds of doped TiO2.
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Zhao, Wenyue, Hua, Wenjing, Wang, Yin, Shi, Lei, Fei, Wei-Dong, and Zhao, Yu
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DIELECTRIC loss , *FERROELECTRIC materials , *TITANIUM dioxide , *DIELECTRIC properties , *FERROELECTRICITY , *ELECTRIC dipole moments - Abstract
TiO 2 , a typical incipient ferroelectric material, has been extensively studied for its ferroelectric or dielectric properties, which can be achieved via donor and acceptor co-doping. However, the influence of doping ions on the performance of TiO 2 remains unclear. In this study, the relationship between the properties of TiO 2 and doping ions was investigated by selecting acceptors with various ionic radii. Colossal permittivity in TiO 2 was achieved by doping large-ionic-radius acceptors, forming defect complexes to pin electrons and mitigate dielectric loss. For small acceptor ionic radii, donor–acceptor co-doped TiO 2 exhibited ferroelectricity at room temperature. The electric dipole moment formed by the donor and acceptor readily rotated under an external electric field, resulting in ferroelectricity at room temperature. This study provides a design perspective for the selection of doping ions to achieve various properties in rutile-type TiO 2 ceramics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Solution derived transparent PZT/FTO heterojunction and its high-temperature ferroelectric photovoltaic effect.
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Li, Zishuo, Song, Jianmin, Huang, Shiying, Li, Haoyang, Ju, Xiangrong, Zhang, Xinyan, Ou, Jiali, Sun, Hailing, Lu, Xubing, and Zhou, Guofu
- Subjects
- *
FERROELECTRICITY , *PHOTOVOLTAIC effect , *FERROELECTRIC thin films , *FERROELECTRIC capacitors , *HETEROJUNCTIONS , *SOLAR energy conversion - Abstract
Ferroelectric photovoltaic (PV) materials have garnered considerable interest because of their distinctive switchable PV characteristics. Nevertheless, their ability to function within a wide range of ambient temperatures was previously constrained. This paper describes the construction of ferroelectric capacitors featuring an Au/PZT (Pb(Zr 0. 40 Ti 0.60)O 3)/FTO (SnO 2 :F) heterojunction through the utilization of the sol-gel technique. The performance analysis findings indicate that the PZT material, following optimization of annealing temperature, displayed strong ferroelectric properties and notable frequency-dependent dielectric behavior. An increase in temperature (25°C∼300°C) revealed that short-circuit current density J sc exhibited an upward → downward → upward trend and reached 399.6 μA/cm2 at 300°C. Energy band analysis showed the presence of spontaneous polarization and a large work function difference between the bottom electrode FTO and the top electrode Au (∼0.42 eV) created a strong built-in electric field in the PZT films, which was conducive to the photogenerated carriers' separation and greatly improved the PZT film ferroelectric PV. In this paper, transparent ferroelectric materials were demonstrated for the first time to exhibit a photoelectric responsivity of up to 1.77 mA/W at a temperature of 300°C, offering a practical strategy for the implementation of transparent ferroelectric photovoltaic devices in high-temperature environments, particularly those subjected to intense solar energy harvesting and conversion. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
33. On the solubility of Bi in tetragonal tungsten bronzes.
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Zeiger, Caren Regine, Williamson, Benjamin Albert Dobson, Walker, Julian, Einarsrud, Mari-Ann, and Grande, Tor
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TUNGSTEN bronze , *LEAD-free ceramics , *MORPHOTROPIC phase boundaries , *UNIT cell , *SOLUBILITY , *PARASOCIAL relationships , *SOLID solutions - Abstract
Ferroelectric Pb 5 Nb 10 O 30 (PN) tetragonal tungsten bronze (TTB) forms solid solutions that exhibit morphotropic phase boundaries (MPBs). Successful replacement of PN with TTBs containing Bi could advance lead-free TTB MPBs. The most studied Bi containing TTB, K 4 Bi 2 Nb 10 O 30 , was recently demonstrated to be paraelectric, and we have systematically explored the possibility to increase the Bi-content beyond two Bi3+ ions per unit cell aiming to induce ferroelectricity. Higher Bi content was incorporated by either increasing the cation vacancy concentration on the A-site or by B-site substitution with lower valency cations. An additional pyrochlore phase was found in almost all the explored compositions exceeding two Bi3+ per unit cell. The instability of the TTB structure with higher Bi3+ concentrations was investigated in terms of first-principles calculations, combined with chemical considerations and including the tolerance factor. Consequently, an in-plane polarisation found in PN is unlikely to exist in Bi-based TTBs, meaning that Bi3+ cannot fully replace Pb2+ in ferroelectric TTBs. [ABSTRACT FROM AUTHOR]
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- 2024
- Full Text
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34. Bulk photovoltaic effect of ferroelectric Sc-doped GaN thin films toward self-powered light detection.
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Wu, Jiali, Shi, Zhaoxiaohan, Bai, Zhongwei, Peng, Tao, and Luo, Bingcheng
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FERROELECTRIC thin films , *PHOTOVOLTAIC effect , *FERROELECTRICITY , *THIN films , *GALLIUM nitride , *FERROELECTRIC materials - Abstract
Gallium nitride (GaN), one of the most popular optoelectronic materials in the semiconductor industry, has gained renewed interest as a ferroelectric material when alloyed with scandium. However, the inherent bulk photovoltaic effect (BPE) of GaN-based ferroelectrics has yet to be fully exploited. In this work, a BPE-driven self-powered photodetector based on ferroelectric Sc-doped GaN thin film was fabricated without the usage of a p - n contact. At zero bias, this device features a high responsivity of 45.9 mA/W, a high detectivity of 2.27 × 1011 Jones, a fast response speed of sub-ms-level, a high UV selectivity of 91.3, and an imaging capacity. This work demonstrates the potential of GaN-based ferroelectric thin films in energy-efficient optoelectronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Photovoltaic and resistance switching properties of NiO/Pb0.92La0.08(Zr0.52Ti0.48)O3/LaNiO3.
- Author
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Bian, Weibai, Zhang, Ruixuan, and Jia, Jiqiang
- Subjects
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PULSED laser deposition , *CURRENT-voltage characteristics , *ELECTRIC fields , *OPEN-circuit voltage , *PHOTOVOLTAIC effect , *ELECTRONIC equipment , *FERROELECTRICITY - Abstract
Due to its excellent ferroelectricity and photovoltaic effect (PE), Pb 0.92 La 0.08 (Zr 0.52 Ti 0.48)O 3 (PLZT) has considerable application potential in the field of multifunctional electronic devices. In this study, an Ag/NiO/PLZT/LaNiO 3 structure is prepared on a Si substrate via a combination of sol–gel and pulsed laser deposition methods, and its ferroelectricity, PE and resistance switching (RS) properties are studied in detail. With decrease in temperature, coercive field of PLZT increases, and its residual polarization initially remains constant and then decreases. The results of ultraviolet-irradiation experiments show that the photogenerated open-circuit voltage (V o) of PLZT first increases slightly and then decreases slightly as the temperature decreases. By changing the direction of PLZT polarization, the polarization field can be oriented in the same direction or opposite to the built-in electric field formed by p – n junction at NiO/PLZT interface. Thus, the total electric field required to drive the photogenerated carriers inside the structure can be tuned, which results in different V o values. Furthermore, current–voltage characteristics of the structure are tested. It is found that as different polarization charges are generated at the NiO/PLZT interface for different PLZT polarization directions, the holes in NiO can be attracted or repelled by these polarization charges. Thereby, the interface barrier height of the p – n junction can be varied. Consequently, the structure exhibits a pronounced RS effect suitable for multilevel storage applications. These results represent an important experimental basis for the development and application of multifunctional electronic devices for optoelectronics and RS-based memories. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. Optimized hybrid improper ferroelectricity of (Ca1-xNdx)3Ti2O7 ceramics based on soft doping effects.
- Author
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Wu, Hongdi, Cai, Wei, Liu, Zhiqiang, Chen, Dakai, Gao, Rongli, Chen, Gang, Deng, Xiaoling, Wang, Zhenhua, Lei, Xiang, and Fu, Chunlin
- Subjects
- *
FERROELECTRICITY , *FERROELECTRIC ceramics , *CERAMICS , *LEAD-free ceramics , *SOL-gel processes , *DOPING agents (Chemistry) - Abstract
Low remnant polarization and high coercive field are the main factors limiting the practical application of Ca 3 Ti 2 O 7 -based hybrid improper ferroelectric ceramics. Based on sol-gel method and soft doping effect, (Ca 1- x Nd x) 3 Ti 2 O 7 (x= 0.003) ceramics with higher remnant polarization of ∼3.53 μC/cm2 and lower coercive field of ∼91 kV/cm were obtained. More interestingly, thanks to the large distortion amplitude of TiO 6 octahedron and effective suppression of defects such as oxygen vacancies caused by Nd3+ as a donor dopant, the remnant polarization of (Ca 1- x Nd x) 3 Ti 2 O 7 (x = 0.003 and 0.006) ceramics measured at 10 Hz using the DHM mode were as high as 7.33 μC/cm2 and 5.85 μC/cm2. These findings prove that the soft doping at A sites of Ca 3 Ti 2 O 7 material is a simple and effective strategy to enhance its hybrid improper ferroelectricity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
37. Defects engineered ferroelectricity and electrocaloric effect in Pb0.7Ba0.3ZrO3 ceramics.
- Author
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Yu, Mengjiao, Li, Feng, Wang, Lifan, Long, Mingsheng, Gong, Weiping, Shan, Lei, and Wang, Chunchang
- Subjects
- *
PYROELECTRICITY , *FERROELECTRICITY , *CERAMIC capacitors , *PIEZOELECTRICITY , *POINT defects , *RIETVELD refinement , *CRYSTAL defects - Abstract
Point defects play a versatile role in modulating ferroelectricity and piezoelectricity, however, the decisive role of point-defect concentration/species in controlling macroscopic performance remains unknown. In this work, defects are implanted by reduced atmosphere annealing and/or Mn doping in Pb 0.7 Ba 0.3 ZrO 3 ceramics. i) defects induce lattice distortion, internal lattice strain and accordingly, phase structure is changed (Williamson-Hall analysis and Rietveld refinement); ii) ferroelectricity is enhanced for 0 MN and 1 MA sample with contribution of defect polarization (first-order reversal curves). iii) Joule heat is depressed as an enhanced resistivity by carrier annihilation/forming defect complex; iv) ECE behaves distinctly among 0 MN, 1 MA and 1 MH, respectively. 0 MN sample exhibits a ΔT max of 0.39 K and 1 MA possesses a ΔT max of 0.34 K. Interestingly, a broad temperature span with a low instability of ∼20 % within 288 K–423 K is obtained in 1 MH sample. This work not only provides a guideline for defects enhancing ferroelectricity and ECE, but also clarifies the reduction-resistant properties of (Pb, Ba)ZrO 3 system that are suitable for constructing base-metal multilayer ceramic capacitors in solid-state cooling devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Structural, optical, dielectric, and ferroelectric properties in [formula omitted] ceramics prepared by a solvothermal reflux approach.
- Author
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Younas, U., Atif, M., Sahil, M., Ali, T., Arshad, M., Khalid, W., Ali, Z., and Nadeem, M.
- Subjects
- *
FERROELECTRICITY , *DIELECTRICS , *ENERGY storage , *ENERGY density , *X-ray photoelectron spectroscopy , *DIELECTRIC properties , *FERROELECTRIC ceramics , *HYSTERESIS loop , *MICROWAVES - Abstract
Chromium ( C r 3 + ) doped B a T i 1 − x C r x O 3 (x = 0.0, 0.03, 0.06, and 0.09) ceramics were prepared by the solvothermal reflux approach. X-ray diffraction analysis confirmed the development of tetragonal structures with P 4 m m symmetry in the prepared samples. The SEM analysis showed that C r 3 + doping resulted in a microstructure that was dense, uniform, and had smaller grains. Surface chemical information and oxidation states were studied using X-ray photoelectron spectroscopy. The diffuse reflectance spectrum confirmed the effect of C r 3 + content on the direct optical bandgap of B a T i 1 − x C r x O 3 samples which shifts from 3.21 eV to 2.73 eV with increasing C r 3 + content. Dielectric permittivity was found to increase in the low-frequency region with increasing C r 3 + doping content up to x = 0.06, while it decreased in the high-frequency region compared to an undoped sample. The observed behavior of permittivity might be explained in terms of the formation of oxygen vacancy defects and their effects on the polarization dynamics of the material. Moreover, the addition of C r 3 + doping had a strong effect on the ferroelectric characteristics, as seen by the formation of a pinched hysteresis loop, resulting in the improvement of energy storage properties. Based on the obtained results, the sample with x = 0.06 exhibited an enhancement of about 3.3 times in energy discharge density and 26 % in storage efficiency compared to the undoped sample. This might be due to a large difference between the values of maximum and remnant polarizations, reduced tangent loss, and a smaller grain size, which makes this material attractive for use in energy storage devices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Great enhancement of ferroelectric properties of Al2O3-modified BiFeO3 thin films obtained by sol-gel method.
- Author
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Zhai, Yining, Fan, Anlong, Zhong, Kangyu, Karpinsky, Dmitry V., Gao, Qi, Yi, Jiaojiao, and Liu, Lisha
- Subjects
- *
SOL-gel processes , *FERROELECTRIC thin films , *ALUMINUM oxide , *THIN films , *CERAMICS , *FERROELECTRIC ceramics , *THIN film devices - Abstract
Thin films prepared by sol-gel method usually have a large leakage current, which hinders their practical applications. Therefore, it is extremely important to adopt effective strategies to reduce their leakage current. In this work, BiFeO 3 thin films with Al 2 O 3 modification, either in the format of layer insertion or evenly-distributed particles incorporation, are fabricated by a sol-gel method on the Pt(111)/Ti/SiO 2 /Si substrates. It was found that an optimal amount of Al 2 O 3 in the system can greatly compress the leakage current and enhance the ferroelectric properties. For BiFeO 3 films with thickness in the ∼300 nm range, remnant polarization (P r) of ∼ 40.82, 80.08, 61,6 μC/cm2, and maximum polarization (P max) of ∼ 62, 157, 90 μC/cm2 can be achieved for Al 2 O 3 modification via 1/3, 1/5 layer insertion and 1:5 particle incorporation, respectively. Additionally, we systematically investigated the impact of Al 2 O 3 on the phase microstructure, leakage current, and conduction mechanism behavior of Al 2 O 3 -modified BiFeO 3 films. The results not only promote the sol-gel method as a promising method for preparing high-quality ferroelectric thin films with compressed leakage, but also promote the potential applications of BiFeO 3 thin films in electromechanical devices. • BiFeO 3 films with Al 2 O 3 modification, either in the format of layer insertion or evenly-distributed particles, are fabricated by sol-gel method. • An optimal amount of Al 2 O 3 can greatly enhance the ferroelectric properties. • The band bending at the Al 2 O 3 /BiFeO 3 interfaces and the resultant build-in electric field counteract the external electric field and increase the breakdown field strength, thus obtaining the superior ferroelectric properties. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Ferroelectricity in Zn1-xMgxO solid solutions.
- Author
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Martínez-Aguilar, E., Hmŏk, H'Linh, Herrera, O.Raymond, Siqueiros, J.M., and López-Juárez, Rigoberto
- Published
- 2023
- Full Text
- View/download PDF
41. Visualizing sintering process and electrical properties of SnO2 doped K0.48Na0.52NbO3 piezoelectric ceramics.
- Author
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Tian, Yongshang, Ma, Mingyang, Li, Shuiyun, Ma, Xin, Wu, Haitao, Ji, Xiang, Wang, Jinshuang, and Jing, Qiangshan
- Subjects
- *
LEAD-free ceramics , *PIEZOELECTRIC ceramics , *STANNIC oxide , *PIEZOELECTRICITY , *THERMOGRAPHY , *FERROELECTRICITY , *SINTERING - Abstract
In this study, the conventional solid-state sintering of lead-free (1− x)K 0.48 Na 0.52 NbO 3 - x SnO 2 piezoelectric green bodies was analysed using thermal imaging and longitudinal/transverse shrinking. The phase structure, fracture morphology, densification, permittivity, ferroelectricity, piezoelectricity, and domain-switching activation energy were investigated with increasing SnO 2 content (x). Sn4+ first occupied the A site in the ABO 3 structure and then substituted the B site with increasing x. This resulted in various contents of defect dipoles and oxygen vacancies, which were mainly responsible for the different ferroelectricity and piezoelectricity values. The permittivity and domain-switching activation energy were significantly affected by the local compositional disorder or fluctuation. Moreover, the influences of phase, densification, fine grain size, and domain wall on the electrical properties are also discussed. The optimum electrical properties, with P r = 34.7 μC/cm2, d 33 = 294 pC/N, and T C = 337 °C were determined for x = 0.30 mol%. This study provides a specific explanation and reference for the various electrical properties of lead-free piezoelectric ceramics. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
42. Dielectric and room temperature ferromagnetism in vacuum annealed Bi(Zn0.5Zr0.5)O3 modified PbTiO3 ceramics.
- Author
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Mishra, Manasmita, Sahoo, M.P.K., Pradhan, Lagen Kumar, and Pattanaik, A.K.
- Subjects
- *
FERROMAGNETISM , *RIETVELD refinement , *POLYCRYSTALS , *DIELECTRICS , *DIELECTRIC properties , *DIELECTRIC loss , *FERROELECTRICITY - Abstract
Polycrystalline solid solutions of (1-x)PbTiO 3 -(x)Bi(Zn 0.5 Zr 0.5)O 3 [x = 0.10, 0.20, 0.30] have been synthesized by using solid state reaction method and followed by air annealing (AA)/ vacuum annealing (VA). All the samples show single phase perovskite structure with tetragonal symmetry (P4mm). Structural parameters are calculated using the Rietveld refinement technique. With the help of Scanning Electron Microscope (SEM), the surface morphology of all the samples is recorded at room temperature. The influence of VA on dielectric parameters such as dielectric constant and tangent loss of the synthesized samples are studied and compared with that of AA samples. These results unfold superior dielectric properties of VA samples as compared to AA samples. Intriguingly, the VA samples exhibit exotic ferromagnetism in non-magnetic PbTiO 3 –Bi(Zn 0.5 Zr 0.5)O 3 samples, transforming these into room temperature magneto-electric multiferroics. Besides, both the ferroelectric and ferromagnetic order parameters were found to increase with the increase in Bi(Zn 0.5 Zr 0.5)O 3 doping in PbTiO 3. The enhanced physical properties witnessed in VA PbTiO 3 –Bi(Zn 0.5 Zr 0.5)O 3 samples localized hopping of charge carriers confined to the grain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Composition design of BNBT-ST relaxor ferroelectric ceramics in superparaelectric state with ultrahigh energy density.
- Author
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Yang, Dong, Tian, Junyuan, Tian, Shuo, Yu, Fang, and Ren, Kailiang
- Subjects
- *
ENERGY density , *RELAXOR ferroelectrics , *LEAD-free ceramics , *ENERGY policy , *X-ray diffraction , *ENERGY storage , *FERROELECTRIC ceramics , *FERROELECTRICITY - Abstract
BNT-6BT-based lead-free ceramics have gained significant attention due to their relatively large piezoelectric coefficients and tunable morphotropic phase boundary conditions. In this investigation, SrTiO 3 (ST) was added to BNT-6BT ceramics to fabricate the BNT-6BT- x ST (BNBT- x ST) composition. The impact of ST content on the phase structure and dielectric permittivity of the BNBT- x ST ceramics was studied. The XRD refinement data show that with increasing ST content, the crystal structure of BNBT- x ST ceramics was transformed from the morphotropic phase structure (coexisting tetragonal (P4/mmm) and pseudo-cubic (Pmm) phase) to the pseudo-cubic phase. The dielectric permittivity data of the BNBT-80ST showed that the T m (the maximum permittivity temperature) moved to −61.9 °C, which caused the room temperature to fall within the range of T m < T < T B (the Burns temperature). This makes the BNBT-80ST a superparaelectric state in relaxor ferroelectrics (RFE). Furthermore, the maximum energy density and the charge-discharge efficiency of the BNBT-80ST achieved 5.48 J/cm3 and 87% at 495 kV/cm, respectively. The energy density of the BNBT-80ST was improved by 2.97-fold and 49% compared with that of the BNBT-30ST and BNBT-70ST. This is mostly attributed to weakened ferroelectricity and improved paraelectricity in the BNBT-80ST. This investigation demonstrates that BNBT- x ST ceramics can be adjusted to a superparaelectric state with an ST content of 80%. This makes the material to possess both a large polarization and a high breakdown field. This material holds great promise for high energy density capacitor applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Structural evolution and coexistence of ferroelectricity and antiferromagnetism in Fe, Nb co-doped BaTiO3 ceramics.
- Author
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Hu, Zimeng, Koval, Vladimir, Yue, Yajun, Zhang, Man, Jia, Chenglong, Abrahams, Isaac, and Yan, Haixue
- Subjects
- *
CERAMICS , *FERROELECTRIC ceramics , *ANTIFERROMAGNETISM , *FERROELECTRICITY , *BARIUM titanate , *DOPING agents (Chemistry) , *MAGNETIC hysteresis - Abstract
Multiferroics are materials that exhibit two or more primary ferroic properties within the same phase and have potential applications in sensors, spintronics and memory devices. Here, the dielectric, ferroelectric and magnetic properties of novel multiferroics derived from BaTi 1− x (Fe 0.5 Nb 0.5) x O 3 (BTFN, 0.01 ≤ x ≤ 0.10) ceramics are investigated. Multiferroism in these ceramics is manifested by the coexistence of ferroelectric long-range ordering and antiferromagnetism. With increasing x -value, there is a structural evolution from a tetragonal perovskite to a mixture of tetragonal and cubic phases, accompanied by a decrease in the temperature of maximum permittivity. At room temperature, ferroelectric behaviour is evidenced by the presence of current peaks corresponding to domain switching in the current-electric field loops, while the observation of non-linear narrow magnetic hysteresis loops suggests dilute magnetism. The results indicate that in the x = 0.07 composition the antiferromagnetic order is established through an indirect super-exchange interaction between adjacent Fe ions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Multiferroic properties induced by defect dipoles in thin Ca3Mn2O7 films at room temperature.
- Author
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Zhao, Wenyue, Wang, Zhao, Li, Ze, Peng, Yazhou, Shi, Lei, Hua, Wenjing, Wang, Lidong, Fei, Wei-Dong, and Zhao, Yu
- Subjects
- *
FERROELECTRIC thin films , *THIN films , *FERROELECTRICITY , *PHOTOVOLTAIC effect , *FERROELECTRIC crystals , *MULTIFERROIC materials , *LEAD titanate - Abstract
Improper ferroelectrics are a class of materials with the potential to design multiferroic properties. In this paper, we report on the effect of defect dipoles on the ferromagnetic and ferroelectric properties of Ca 3 Mn 2 O 7 improper ferroelectric thin films. Two kinds of defects dipoles, Mn3+-oxygen vacancy (Mn3+- V O ∙ ∙ ) and Li+-Al3+ doping, were studied. The experimental results show that both Mn3+- V O ∙ ∙ and Li+-Al3+ defect dipoles can introduce ferromagnetism in the films, and Li+-Al3+ defect dipole can also improve ferroelectricity with self-polarization. The first-principle calculations based on local density approximation demonstrate the local lattice distortion, including title MnO 6 octahedron and off-center displacement of Mn ion, plays crucial role in multiferroic properties of the film. This work gives an effective method to design the ferroelectricity and ferromagnetic properties in improper ferroelectric oxides with layered structure through constructing defect dipoles. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Broadband, high-sensitivity self-powered ferroelectric LuMnO3-based photodetector with large photocurrent output.
- Author
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Gong, Ao, Zhang, Shan, Li, Yong, Han, Pei, Lu, Chunxiao, Sun, Ningning, Zhao, Ye, Xing, Lei, Zhang, Liwen, and Hao, Xihong
- Subjects
- *
PHOTODETECTORS , *PHOTOCATHODES , *FERROELECTRICITY , *FERROELECTRIC materials , *PHOTOVOLTAIC effect , *MONOCHROMATIC light , *TRIBOELECTRICITY , *SHORT-circuit currents - Abstract
The broadband spectrum detection from ultraviolet to near-infrared is hankered in the photoelectric applications of imaging, sensing and communication. Here, a new self-powered photodetector based on ferroelectric LuMnO 3 thin film with a narrow bandgap of 1.46 eV exhibits high-sensitivity ultraviolet–visible–near infrared photodetection properties. The responsivity (R) and detectivity (D *) in sunlight are 0.4 A/W and 7.05 × 1011 Jones, which are much higher than that of other ferroelectric photodetectors. Moreover, under the monochromatic light (900 nm), the R and D * can reach 0.39 A/W and 6.89 × 1011 Jones. The outstanding photodetection performances owed to the large photocurrent output, where the short-circuit current density can reach 10.5 mA/cm2 under 1 sun illumination. The synergistic effect of ferroelectric photovoltaic effect and interface barrier effect demonstrates that the multi-driving forces can achieve high dissociation efficiency for photon-generated carriers. The excellent photodetection performances open up new application of ferroelectric materials in broadband self-powered photodetectors. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Effect of Y2O3 interlayer on the electric properties of Y-doped HfO2 film deposited by chemical solution deposition.
- Author
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Zhang, Weiqi, Sun, Nana, and Zhou, Dayu
- Subjects
- *
CHEMICAL solution deposition , *ELECTRIC properties , *BREAKDOWN voltage , *SURFACE energy , *VOLTAGE dividers , *STRAY currents - Abstract
Ferroelectric oxide becomes the focus of memory industry again after the discovery of ferroelectricity in doped-HfO 2 polycrystalline films. Thermal stress is an important factor for the variation of ferroelectric phase content. In this paper, the effect of film stress induced by Y 2 O 3 interlayer in the ferroelectric properties of Y-doped HfO 2 (Y: HfO 2) ferroelectric films, which is deposited by chemical solution deposition (CSD), is investigated systematically by polarization-voltage measurement. Compared with Y-doped HfO 2 film without interlayer, 1 nm Y 2 O 3 interlayer enhances the remanent polarization of Y: HfO 2 film due to the effects of film stress and surface energy. And thick Y 2 O 3 interlayer benefits to reduce leakage current density. But polarization switching of HfO 2 film is restrained due to the capacitor voltage divider caused by thick Y 2 O 3 interlayer. The obvious enhance effect of Y 2 O 3 interlayer still exists in Y: HfO 2 film at high voltage due to the breakdown of Y 2 O 3 interlayer, realizing a huge remanent polarization (P r) of 22.8 μC/cm2 in Y: HfO 2 film (doping content: 4 at %). It is 3.6 times than that of ferroelectric doped-HfO 2 film without Y 2 O 3 interlayer. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. Defect induced polar distortion in SrMnO3 thin films.
- Author
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Yoon, Chang Jae, Anoop, Gopinathan, Park, Seong Min, Son, Yeong Jun, Kim, Tae Yeon, Unithrattil, Sanjith, Han, Gyeongtak, Kim, Young-Min, Kim, Gi-Yeop, Choi, Si Young, Cho, Seongwoo, Hong, Seungbum, and Jo, Ji Young
- Subjects
- *
SCANNING transmission electron microscopy , *STRAINS & stresses (Mechanics) , *OXIDE coating , *THIN films , *SUBSTRATES (Materials science) , *ELECTRON energy loss spectroscopy - Abstract
[Display omitted] • Defect engineering stabilizes polar states in non-polar SrMnO 3 (SMO) thin films. • Polar distortion induces defects in SMO films on Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 substrates. • Strain gradient and defect chemistry induce polar state at room temperature. • Potential applications in electric field-controlled magnetic devices. Defect engineering in perovskite oxides enables novel functionalities by inducing and controlling lattice defects, effectively breaking lattice symmetry, stabilizing polar states and inducing ferroelectricity in non-polar/paraelectric or ferro/antiferromagnetic oxide thin films. A polar state can be stabilized in SrMnO 3 (SMO) thin films by displacing Mn ions. However, conventional epitaxial strain engineering necessitates deposition on diverse single crystalline substrates with varying misfit strains and optimization of thin film growth conditions, posing challenges in achieving polar states in SMO thin films. In this study, polar distortion was achieved by inducing defects in SMO epitaxial thin films grown on Pb(Mg 1/3 Nb 2/3)O 3 -PbTiO 3 substrates La 0.7 Sr 0.3 MnO 3 (LSMO) electrode. Scanning transmission electron microscopy analysis revealed that Mn ion displacement and the c/a ratio increased on moving from the SMO/LSMO interface to the top surface of the SMO film. Electron energy loss spectroscopy depth profiles revealed variations in oxygen stoichiometry and Mn3+/Mn4+ ratio across the cross section of the SMO film. Consequently, a polar state was stabilized through strain gradient induced by defect chemistry in SMO thin films. Our study demonstrates that defect engineering can be effectively utilized in the realization of electric field-controlled magnetic devices at room temperature. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
49. Ferroelectric polarization-electric field promoted S-scheme CdSe/BaxSr1-xTiO3 for highly efficient solar hydrogen evolution.
- Author
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Wang, Meiyang, Yu, Han, Yang, Nan, and Yu, Kai
- Subjects
- *
POLARIZATION (Electricity) , *FERROELECTRICITY , *ELECTRIC fields , *ELECTRON transport , *CHARGE transfer - Abstract
[Display omitted] • A novel ferroelectric assisted CdSe/B x ST photocatalysts was fabricated via in-situ growth route. • CdSe/B 0.8 ST exhibited excellent H 2 evolution rate of 1971.8 µmol g−1 h−1 without noble metal cocatalyst. • The synergistic effect of ferroelectric polarization and internal electric field promote the charge transfer efficiency was proposed. • S-scheme heterostructure could preserve the strong redox potential and improve charge separation. Coupling the ferroelectric polarization and internal electric field to realize effective separation and migration of photogenerated charges is highly attractive for accomplishing efficient photocatalytic hydrogen production. In this work, an internal electric field modulated S-scheme heterostructure was fabricated by depositing CdSe on ferroelectric Ba x Sr 1-x TiO 3 (B x ST) through an in-situ growth method. Because of the oriented powerful electron transport driven by the strong spontaneous polarization and internal electric field, the as-synthesized CdSe/B x ST heterojunctions demonstrated excellent solar to H 2 performance. Without the addition of noble metal cocatalyst, 7% CdSe/B 0.8 ST exhibited a H 2 evolution rate of 1971.8 µmol g-1 h−1 with an apparent quantum yield of 12.1% at 365 nm. Moreover, the obtained heterojunction catalysts exhibit good stability after 12 h continuous irradiation. This work provides a viable strategy on the utilization of ferroelectric polarization and internal electric field strategy to promote charge transfer and separation of S-scheme photocatalysts. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
50. Strain-tunable robust ferroelectricity in two-dimensional monochalcogenide heterostructures.
- Author
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Paudel, Ramesh and Alpay, S. Pamir
- Subjects
- *
LANDAU theory , *BAND gaps , *PHASE transitions , *DENSITY functional theory , *DYNAMIC stability - Abstract
[Display omitted] • Negative formation energies, positive phonon modes, and AIMD simulations confirm the stability of the MLs and the heterostructure. • SnS/GeSe heterostructure exhibits a direct band gap, indicating that this system can be used in optical devices. • A smooth paraelectric-ferroelectric phase transition in SnS/GeSe, is explained by phonon dispersions and Landau theory. • Our results indicate that the spontaneous polarization of the SnS/GeSe construct can be controlled via in-plane strains. Low-dimensional layered ferroelectric van der Waals heterostructures (vdWHs) are of tremendous interest for novel nanoscale electronic applications, including nonvolatile memories, transistors, and sensors. Here, we design SnS/GeSe multilayer vdWHs and show that the construct is ferroelectric with a spontaneous polarization of 3.71 × 10-10 Cm−1. We computationally analyze SnS and GeSe monolayers (MLs) and SnS/GeSe heterostructures using density functional theory (DFT) with van der Waals (vdW) correlations. Specifically, we determine structural parameters, formation energies, polarization, and phonon modes. Negative formation energies with real frequencies of phonon spectra confirm the (relative) stabilities of SnS and GeSe monolayers (MLs) and SnS/GeSe heterostructures. The electronic properties of both monolayers are retained in the SnS/GeSe construct, which exhibits a direct band gap with a value of 1.13 eV. The calculations of phonon spectra and double-well potential of monolayers unveil a Pnm21 ferroelectric – Pnmm paraelectric phase transformation. The SnS/GeSe multilayer shows the largest spontaneous polarization of 3.71 × 10-10 Cm−1 compared to 2.78 × 10-10 Cm−1 and 3.69 × 10-10 Cm−1 for SnS- and GeSe-MLs, respectively. Additionally, we demonstrate that the spontaneous polarization, band gap, dynamic stability, and band gap types of SnS/GeSe heterostructures can be tuned through the application of biaxial strains. For an in-plane 5 % tensile strain, SnS/GeSe has a spontaneous polarization of 3.90 × 10-10 Cm−1. The band gap of the SnS/GeSe heterostructure widens with increasing tensile biaxial strain, maintaining its characteristics as a direct band gap semiconductor up to 2 % tensile strain. These findings demonstrate that SnS/GeSe heterostructures are promising materials with significant potential for applications in nanoelectronics. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
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