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The Zr37Hf16Ni12.5Cu12.5Al11Co6Nb5 bulk metallic glass (BMG) with strong glass-forming ability (GFA) and remarkable mechanical properties was designed, and its thermophysical properties were characterized simultaneously. The glass transition temperature reached up to 726 K, while the fragility index of 43 was derived by measuring alloy viscosity. The undercooled liquid of this BMG with such a low fragility index displayed a strong liquid behavior, corresponding to its small crystallization driving force and high GFA. The thermal expansion coefficient increased from 9.76 × 10−6 K−1 of glassy state to 2.71 × 10−5 K−1 of undercooled liquid, and the close-packed structure was evidenced by the low specific energy for free volume formation of 239.4 kJ/mol. Owing to its low free volume and high glass transition temperature, this BMG exhibited remarkable tensile and compressive yield strengths up to 1660.3 and 2042.3 MPa, respectively. [ABSTRACT FROM AUTHOR]

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]

The phase selection mechanism within undercooled liquid Nb90Si10 hypoeutectic alloy was investigated by electrostatic levitation technique combined with deep neural network molecular dynamics. A stepwise-solidification procedure was conducted, where the primary phase and eutectic microstructure successively solidified from undercooled liquid alloy and undercooled residual liquid, respectively. The intermetallic phase of the eutectic structure transfers from Nb3Si to βNb5Si3 and finally into αNb5Si3 compound with the increase in liquid undercooling. The deep neural network molecular dynamic simulations have shown that the phase selection between Nb3Si and Nb5Si3 is mainly controlled by the short-range order of residual liquid, considering that the predominant short-range configuration transforms from Nb3Si-like to Nb5Si3-like structures. The αNb5Si3-like medium-range order, which is characterized by vertex-connected ⟨0,2,8,4⟩ clusters, is shown to significantly influence the competitive nucleation of the αNb5Si3 and βNb5Si3 phases. The residual liquid favors the αNb5Si3-like medium-range order rather than βNb5Si3 at large undercoolings, which explains the transformation from βNb5Si3 to αNb5Si3. [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]

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]

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]

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]

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]

The liquid Zr100-xSix (x = 1, 3, and 5) alloys were substantially undercooled by up to 392 K (0.19TL), 423 K (0.21TL), and 451 K (0.23TL), respectively, under the electrostatic levitation condition. The measured dendrite growth velocity of the primary βZr phase increased with the enhancement of liquid undercooling. Although the undercooling ability showed an increasing tendency with the increase in the Si content, dendrite growth was obviously depressed due to the dominance of solute diffusion controlled growth. Their critical undercoolings for kinetics transition from solute diffusion to thermal diffusion controlled growth were determined. It demonstrates a remarkable refinement of dendrites and an increasing trend of Si solubility in αZr dendrites with increasing undercooling. [ABSTRACT FROM AUTHOR]

Electrical transport properties of La2/3Sr1/3VO3 (LSVO) thin films grown on LaAlO3 (LAO) and SrTiO3 (STO) substrates have been investigated. It is found that the LSVO/LAO show metal-insulator transition when decreasing the temperature, while the LSVO/STO exhibit metallic behavior. The difference in transport properties of LSVO thin films has been discussed based on the variation of oxygen content and can be attributed to different oxygen substrate-to-film transfer. These results highlight the crucial role of oxygen stoichiometry in determining the physical properties of LSVO and the importance of oxygen-substrate contribution in LSVO thin films. [ABSTRACT FROM AUTHOR]

The valence band offset (VBO) of a n-ZnO/p-MgxNi1-xO heterojunction grown by pulsed laser deposition was investigated by x-ray photoelectron spectroscopy. From the directly measured VBO of 1.64 ± 0.05 eV, a -2.26 ± 0.05 eV conduction band offset was derived. This indicates that the ZnO/MgxNi1-xO heterojunction has a type-II (staggered) band alignment. The conduction band minimum (CBM) of the n-ZnO/p-MgxNi1-xO heterojunction shifts to higher energy with Mg doping relative to the n-ZnO/p-NiO heterojunction. Thus, the position of the CBM can be controlled by the Mg concentration. [ABSTRACT FROM AUTHOR]

Effects of light and electrical current on the electrical transport properties of oxygen-deficient La7/8Sr1/8MnO3-δ thin films have been investigated. The light illumination causes a resistance drop to show photoconductivity effect. Moreover, the photoconductivity can be remarkably enhanced by increasing the electrical current, that is, it exhibits current-enhanced photoconductivity (CEPC) effect. The CEPC ratio achieves 80% at 300 K with light intensity of 56.7 mW cm-2 and electrical current of 20 μA. The phenomena are explained by a photoinduced localized insulator-metal transition and stabilization of conducting paths by the electrical current. These results may be important for practical applications in photoelectric devices. [ABSTRACT FROM AUTHOR]