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To obtain high energy storage density in ferroelectric films, polarization and breakdown field Eb are two crucial factors. The inversely coupled relationship between polarization and Eb is commonly observed and it remains a challenge to realize high E b without deteriorating polarization. Selecting a suitable element doping should largely enhance the Eb since of the optimization of microstructures as well as the decrease in defects, meanwhile the doping should induce extra polarization contribution from lattice distortion. In this work, we reported that Eb can be largely enhanced via Mn doping in BaBi4Ti4O15 thin films due to grain refining, densification, and oxygen vacancy reduction. Interestingly, the polarization is not deteriorated since of the Mn doping effect induced extra polarization from the lattice distortion. Consequently, an ultrahigh energy storage density of 96 J/cm3 with a high efficiency of 76.6% was achieved in BaBi4Ti3.95Mn0.05O15 thin films with excellent stability and reliability. This work will provide a simple and effective route to improve the energy storage in dielectric capacitors. [ABSTRACT FROM AUTHOR]

The development of high-performance optically induced voltage materials represents a significant challenge within the realm of optical detection. The constraints posed by low induced voltage and extended response times have impeded the practical applicability of optical and thermal radiation detectors. In this investigation, we propose the utilization of superconducting Bi2Sr2CuOy (Bi-2201) as a pulsed laser-induced voltage material, revealing the emergence of notable transverse voltage signals in tilted thin films. A noteworthy peak voltage of 25.12 V is attained upon exposure to ultraviolet pulsed laser (248 nm), with a rapid rise time of merely 60 ns. Furthermore, we establish an empirical equation specific to our laser detection heterostructure, serving as a benchmark for Bi-2201-based laser detection systems. These findings introduce a promising avenue for the expanded practical applications of high-temperature superconductors. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide MoS2 is considered as a type of dielectric loss dominated electromagnetic wave absorbing material owing to the high specific surface area, layered structure, and lightweight. Introduction of interfaces will improve the electromagnetic wave absorbing performance. Here, the phase engineering of MoS2 is realized through W doping since of the microstrain effect, resulting in the appearance of 2H/1T MoS2 phase interface. Furthermore, MoS2/Ti3C2 MXene interface is realized through the construction of MoS2/Ti3C2 MXene heterostructure, leading to obvious improvements in electromagnetic wave absorbing. Because of the simultaneous introduction of 2H/1T MoS2 phase interface and the MoS2/Ti3C2 MXene interface, the microwave reflection loss can reach −45.2 dB with broad effective absorption bandwidth (<−10 dB) of 7.1 GHz (7.8–14.9 GHz) at the same thickness of 3 mm. The results shed light on enhancing electromagnetic wave absorbing performance by phase engineering as well as construction of two dimensional material/two dimensional material heterostructures, thereby introducing multiple interfaces. [ABSTRACT FROM AUTHOR]

Lead-free Na0.5Bi0.5TiO3 (NBT) exhibiting large polarization and a high Curie temperature can be considered as a promising candidate for dielectric capacitors. The large polarization switching hysteresis and low breakdown field, however, restrict the performance optimization. Herein, epitaxial NBT-based high-entropy Na0.5Bi0.5Ti0.7Hf0.1Zr0.1Sn0.1O3 (NBTHZS) films are designed and prepared by solution-based processing. Compared with the NBT film, the polarization switching hysteresis is depressed and the breakdown field is significantly improved for the NBTHZS film due to the high-entropy effects. Therefore, the NBTHZS film achieves a ∼16 times enhancement of energy density (from 5.1 J/cm3 of the NBT film to 81 J/cm3 of the NBTHZS film) and a high efficiency of 74.1% as well as an excellent performance reliability. The results shed light on enhancing dielectric energy storage properties of NBT-based films by forming high-entropy structures. [ABSTRACT FROM AUTHOR]

Design and realization of high-efficiency p-type thermoelectric materials with excellent performance are the demand for integrated thermoelectric components. Compared with single crystal bulk materials, thermoelectric thin films are more suitable for the miniaturization of thermoelectric devices. Here, c-axis oriented CuRh1−xMgxO2 (x = 0, 0.05, and 0.1) thin films were prepared and the thermoelectric properties are reported. The power factor of a p-type 10% Mg-doped CuRhO2 thin film shows a large value of 535.7 μW K–2 m-1 at 300 K. The results suggest that the hole-doped CuRhO2 thin films can be regarded as potential p-type thermoelectric oxide and will pave an avenue to develop Rh-based thermoelectric thin films. [ABSTRACT FROM AUTHOR]

The traditional strategy for transparent conducting oxides (TCOs) follows the path of chemical design by increasing carrier concentrations in insulators through deliberate doping to coordinate the exclusive properties of electrical conductivity with optical transparency. Despite the success of n-type TCOs, the developed p-type TCOs based on chemical design exhibit much lower performance than the n-type counterparts primarily constrained by the hole doping trouble. Recently, the correlated metal of a V2O3 thin film has been reported as high-performance p-type TCOs with high hole concentration (>1022 cm−3). In this paper, we propose an alternative approach of compressive strain in V2O3 thin films toward further increasing the carrier concentration and, consequently, enhancing the performance of p-type TCOs. The compressive strain of the V2O3 thin film is realized by the lattice mismatch between V2O3 and Al2O3. Interestingly, carrier concentrations in strained V2O3 thin films can be increased by several times exceeding 1023 cm−3, which directly correlates with the increase (decrease) in a 1 g ( e g π ) orbital occupation as verified by the Raman spectrum. Meanwhile, the screened plasma energy of a strained V2O3 thin film shifts to ∼1.6 eV, which is less than 1.75 eV to assure the opening of the transparency window in the visible region. As a result, strained V2O3 thin films exhibit enhanced performance as p-type TCOs with relatively high figure of merit. These results indicate that the structural modification can open up an effective approach for increasing the carrier concentration and enhancing the performance of p-type TCOs. [ABSTRACT FROM AUTHOR]

We report a quantum paraelectric (QP) to dipolar glass (DG) phase transition induced by Sc substitution in ferrimagnetic hexaferrite BaFe 12 − x Sc x O 19 (0 ≤ x ≤ 2.4) single crystals. The DG behavior is revealed via anisotropic dielectric spectroscopy, polarization, and specific heat measurements. The phase evolution from QP to DG (0.5 ≤ x ≤ 1.2) and finally to the nonpolar state (x ≥ 2.4) with increasing x is found to be due to the competition between the enhanced polar instability by lattice volume expansion and disordered/frustrated dipole-dipole interaction induced by the partial replacement of Sc 3 + for Fe 3 + in the bipyramids. Our results suggest further experimental clues to realize possible multiferroicity with strong displacive ferroelectricity in BaFe 12 O 19 and other magnetic materials. [ABSTRACT FROM AUTHOR]

Epitaxial BaSnO3 (BSO) thin films doped with different rare-earth elements (La, Pr, and Nd) were prepared by a simple solution deposition method. Grain size engineering through processing was achieved to tune both lateral and vertical grain sizes, resulting in obvious increments in carrier mobility. Improved performance with the room-temperature mobility exceeding 35 cm2 V−1 s−1 and resistivity as low as 0.55 mΩ cm was realized. The results will open a low-cost route for preparation of large-area BSO thin films with improved optoelectronic properties through the solution method. [ABSTRACT FROM AUTHOR]

Chiral antiferromagnetic (AFM) Weyl semimetal Mn3Sn shows a large anomalous Hall effect (AHE) around room temperature, due to the Berry curvature generated by Weyl nodes in electronic dispersions. Here, we study the temperature- and angular-dependent Hall effect and magnetic measurement in single-crystalline Mn3Sn. There are some intriguing phenomena: first, a large hysteretic-type AHE has been observed only above 270 K, while the coercivity is around 300 Oe and independent of temperature. Second, the temperature- and angular-dependent topological Hall effect is obtained, which may stem from the real space topological spin texture. Third, the coercivity extracted from the angular-dependent AHE is well fitted with the Stoner-Wohlfarth model, which reflects the evolution of domain walls and magnetic anisotropy. Thus, it shows that not only the topological structure in momentum space but also the real space topological spin texture plays an important role in anomalous transport properties of Mn3Sn. Our work pushes forward to the realization of room temperature AFM spintronics and paves the way toward the possible devices based on the unconventional Hall effect. [ABSTRACT FROM AUTHOR]

We investigate the effect of Jahn-Teller (JT) active Cu2+ ions on the structural, magnetic, and ferroelectric properties of Co1–xCuxCr2O4 (0 ≤ x ≤ 0.4). All the samples can be indexed with a cubic lattice with space group Fd 3 ¯ m at room temperature. All the samples undergo a paramagnetic-ferrimagnetic transition at TC and spiral ferrimagnetic ordering at TS. The magnetization measurements manifest that magnetization reversal occurs in the x = 0.2 and 0.3 samples. The x = 0.3 sample possesses a rather large polarization of 14 μC/m2, which is 7 times in magnitude compared with the CoCr2O4 single crystal. The analysis of the infrared active phonon modes implies that two T 1 u (IR) optical phonon modes are gradually split into a doublet at around 40 K, implying the lowering of lattice symmetry. The presence of a low-symmetry tetragonal phase becomes polar and enhances the electric polarization of Co0.7Cu0.3Cr2O4. [ABSTRACT FROM AUTHOR]

This work reports the structural phase manipulation and the enhancement of microwave absorption in WS2 nanosheets. Large-scale WS2 nanosheets (1T@2H WS2) containing mixed 2H and 1T phases were synthesized by a simple hydrothermal process. The structural characteristics and concentration (∼60%) of the 1T phase in 1T@2H WS2 nanosheets were identified by X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy. With the emergence of the 1T phase, the permittivity of 1T@2H WS2 is more than three times higher than that of WS2 with a pure 2H phase (2H WS2). Moreover, the microwave absorption properties were remarkably enhanced due to the emergence of the 1T phase. Contrary to 2H WS2, in which microwave reflection loss (RL) is close to zero, the RL for 1T@2H WS2 can reach −47 dB with an effective bandwidth (<−10 dB) of 5.2 GHz. In addition, with the adjustment of the thickness of the absorber layer from 1.5 to 5 mm, 1T@2H WS2 can achieve strong absorption in a wide band from 4 to 18 GHz. This finding provides an effective strategy for designing and synthesizing the microwave absorption materials. [ABSTRACT FROM AUTHOR]

Developing lead-free film dielectric capacitors with high-performance of energy storage density, efficiency, fatigue endurance, and thermal stabilities is desirable. Here, we report energy storage properties in (1-x)BaTiO3-xBi3.25La0.75Ti3O12 thin films. It is revealed that a 0.6BaTiO3-0.4Bi3.25La0.75Ti3O12 thin film with a thickness of 280 nm and a crystallization temperature of 650 °C shows a breakdown strength of 3.23 MV/cm with a large polarization value and dielectric constant. An ultrahigh energy storage density of 61.1 J/cm3 and an efficiency of 84.2% are simultaneously achieved at room temperature. Additionally, excellent fatigue endurance after 6 × 109 cycles and good thermal stability up to 150 °C are observed, implying excellent energy storage performance in 0.6BaTiO3-0.4Bi3.25La0.75Ti3O12 thin films. [ABSTRACT FROM AUTHOR]

Thin film ferroelectric capacitors (TFFCs) with excellent energy storage have attracted increasing attention due to the electronic devices toward miniaturization and integration. BiFeO3 (BF)/ Bi3.25La0.75Ti3O12 (BL) based thin films are prepared by chemical solution deposition for energy storage. Ultrahigh energy storage with a recoverable energy density Ure of 54.9 J/cm3 and an efficiency g of 74.4% is observed in the bilayered BF/BL thin films. Further improvement of energy storage is realized in trilayered BL/BF/BL thin films with a Ure of 65.5 J/cm3 and an efficiency g of 74.2% at an electric field of 2753 kV/cm as well as excellent fatigue endurance up to 109 cycles. The results suggest that BF/BL based thin films can be used as lead-free TFFCs in energy storage applications. [ABSTRACT FROM AUTHOR]

As a type of perovskite transparent conducting oxides, La-doped BaSnO3 is considered as a very important material to construct all transparent perovskite devices. The difficulty in achievement of large-area films with high electrical mobility has hindered the development of La-doped BaSnO3 films. Here, we report the results about chemical solution deposition of Ba0.92La0.08SnO3-δ (BLSO) films. The post-annealing and atmosphere as well as lattice mismatch have been investigated. Post-annealing at 1000 °C can obviously improve the performance due to the enhanced crystallization. Under post-annealing in N2 atmosphere the room-temperature resistivity and electrical mobility can achieve 3.25 mΩ cm and 11.09 cm² V-1 s-1, respectively, for the BLSO on LaAlO3 single crystal substrates due to the enhanced oxygen deficiencies. BLSO films with different orientation can be easily obtained by selection of the substrates, showing isotropic physical properties. Furthermore, the room-temperature resistivity and mobility are optimized to 1.8 mΩ cm and 23.04 cm² V-1 s-1 when SrTiO3 single crystal substrates with smaller lattice mismatch are used due to the decreased dislocation density. The results will provide an alternative route to fabricate large-area transparent conducting alkaline-earth stannate films with high performance using low-cost chemical solution deposition. [ABSTRACT FROM AUTHOR]

Environmentally benign Bi3.25La0.75Ti3O12 (BLTO) thin film capacitors were prepared by a cost effective chemical solution deposition method for high energy density storage device applications. Low annealing temperature annealed BLTO thin films showed very slim hysteresis loops with high maximum and small remnant polarization values. Increasing the applied electric field to 2040 kV/ cm, the optimized BLTO thin films show a high recoverable energy density of 44.7 J/cm3 and an energy efficiency of 78.4% at room temperature. Additionally, the BLTO thin film capacitors exhibited excellent fatigue endurance after 4x108 cycles and a good thermal stability up to 140°C, proving their strong potential for high energy density storage and conversion applications. [ABSTRACT FROM AUTHOR]

(1-x)(0.94Bi0.5Na0.5TiO3-0.06BaTiO3)-xBiFeO3 (0 ≤ x ≤0.9) ternary ceramics were prepared by the modified Pechini method. X ray diffraction patterns manifest that the samples undergo a gradual structural transformation from the rhombohedral-tetragonal morphotropic phase boundary to the rhombohedral phase with the increasing content of BiFeO3. Room temperature ferromagnetism was observed in BiFeO3-rich samples with x ≥ 0.6, and this ferromagnetism can be ascribed to the suppression of the spiral spin structure with the canting of antiferromagnetically ordered spins. The BiFeO3-rich samples (x=0.6-0.8) exhibit superior ferroelectric properties with the maximum remanent polarization of 44.7 lC/cm², as confirmed by the positive-up negative-down measurement to exclude the contribution of leakage current. The coexistence of room-temperature ferromagnetism and ferroelectricity manifests that the lead-free BiFeO3-based solid solutions are quite promising multiferroic materials and may be important for potential applications in BFO-based magnetoelectric devices. [ABSTRACT FROM AUTHOR]

The structural, magnetic, and dielectric properties of the YCr0.88Fe0.12O3 single crystals were studied. Detailed magnetic studies demonstrate that the crystal is antiferromagnetic with weak canted ferromagnetism and experiences three sequential magnetic transitions around TN1~127.3K, TN2~115.2 K, and TSR~99.0 K. Interestingly, a temperature induced spin reorientation (SR) near TSR and magnetic field induced SR below TSR were observed. The H-T phase diagram was revealed to be quite different from both parent compounds YFeO3 and YCrO3. A dielectric relaxation around TN1 was found to be associated with electron hopping. An intrinsic magnetoelectric effect was also observed at low temperatures. These results are helpful for understanding the exotic magnetic and magnetoelectric properties in the orthochromite and orthoferrite related systems. [ABSTRACT FROM AUTHOR]

Cr0.68Se single crystals with two-dimensional (2D) character have been grown, and the detailed magnetization M(T), electrical transport properties (including longitudinal resistivity qxx and Hall resistivity ρxy), and thermal transport properties [including heat capacity Cp(T) and thermoelectric power S(T)] have been measured. There are some interesting phenomena: (i) Cr0.68Se presents a non-collinear antiferromagnetic (AFM) semiconducting behavior at the Néeel temperature of TN=42K and with the activated energy of Eg = 3.9 meV; (ii) it exhibits the anomalous Hall effect (AHE) below TN and large negative magnetoresistance about 83.7% (2 K, 8.5 T). The AHE coefficient RS is 0.385 cm-3/C at T=2K, and the AHE conductivity rH is about 1 Ω-1 cm-1 at T=40 K; (iii) the scaling behavior between the anomalous Hall resistivity ρxyA and the longitudinal resistivity ρxx is linear, and further analysis implies that the origin of the AHE in Cr0.68Se is dominated by the skew-scattering mechanism. Our results may be helpful for exploring the potential application of these kinds of 2D AFM semiconductors. [ABSTRACT FROM AUTHOR]

We have investigated the structural, magnetic, and dielectric properties of RFe0.5Cr0.5O3 (R = Nd, Sm, Gd, and Y) compounds. Both structure and magnetic analyses show a Fe/Cr cation disorder, which results in the existence of Fe-rich and Cr-rich clusters. The competition between the moments of the two clusters gives rise to the R-dependent temperature induced magnetization reversal. Interestingly, we also find that the charge carrier hopping in the two clusters leads to two sequential dielectric relaxations in all the samples. In addition, giant magnetocaloric effect with a magnetic entropy change reaching ~29.2 J/kg K was observed with R = Gd. [ABSTRACT FROM AUTHOR]