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Vertically aligned nanostructured (VAN) epitaxial La0.5Ca0.5MnO3 (LCMO) single-phase thin films have been achieved on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] substrates under high magnetic fields applied in pulsed laser deposition processing. Low-field magnetoresistance (LFMR) in the LCMO VAN films can be effectively manipulated through varying the high magnetic field strength. The tunability of VAN on the electrical transport properties is dependent on control of the high magnetic field on the microstructures, including the geometrical arrangement, vertical interfaces, and vertical grain boundaries (GBs). An LFMR value as high as 45% at 150 K and 1 T has been achieved in an LCMO VAN film grown at 10 T, and its LFMR values are larger than 25% at 127–200 K and 1 T. The tunable and enhanced LFMR in the LCMO VAN films over a wide temperature range can be attributed to the increase in vertical interfaces and GB density with the increasing high magnetic field, which are highly related to the spin-polarized tunneling effect. Applying a high magnetic field in film deposition to control the microstructures of VAN single-phase films is a feasible route to achieve tunable and desirable physical properties.

In this study, hole-type high-temperature superconductor Bi2Sr2CaCu2Oy (Bi-2212) with strong electronic correlation is proposed as a p-type transparent conducting oxide (TCO) candidate. Phase-pure and c-axis oriented Bi-2212 thin films with different thicknesses were prepared to investigate the optoelectronic properties. High room-temperature conductivity between 1064 and 200 S/cm with visible transmittance over 50% is obtained for the prepared Bi-2212 thin films. The results will provide an arena to search for p-type TCOs in high-temperature superconductors with strong electronic correlation and give a potential application in the field of transparent metallic contacts as well as transparent correlated metal/n-type semiconductor Schottky diodes.

High coercivity CoFe2O4 (CFO) thin films with large-area are very desirable for applications. Here, we report La0.7Sr0.3MnO3 (LSMO) layer decoration effects on coercivity in CFO thin films by solution processing. With LSMO layer decoration, the coercivity increases initially and then decreases with increasing LSMO layer thickness. Strain induced by the mismatched thermal expansion coefficient and magnetostrictive coefficient as well as the interfacial magnetic exchange coupling between CFO and LSMO are investigated. The room temperature out-of-plane and in-plane coercivity reached 7.6 and 4.9 kOe, respectively, are obtained, which are the highest values in solution derived CFO thin films. The improved coercivity is beneficial for applications and provides a facile route to enhance coercivity of CFO thin films through surface modification by soft magnetic layers.

High room temperature coercivity CoFe2O4 (CFO) thin films are desirable in view of many applications, which is seldom achieved over 3 kOe in solution deposited CFO thin films. Herein, grain growth kinetic is investigated in the solution derived CFO thin films with coercivity larger than 4 kOe, showing a relaxation mechanism. The coercivity and magnetization increase initially and then decrease with increasing dwell time. The high coercivity is originated mainly from the critical grain size and the growth strain induced by the small crystallites and poorly developed grains. The results will provide a route to fabricate larger-area CFO thin films with high coercivity on silicon wafers by low-cost solution processing.

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 ...

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.

Upper critical field of polycrystalline δ-Mo1-xZrxN (0 ≤ x ≤ 0.3) thin films by sol-gel was investigated. It showed that the upper critical field was continuously improved with Zr doping content, and the improvement of ∼10 T in upper critical field was mainly attributed to the combined effects of obvious enhancements in normal-state resistivity with slight changes in Tc, obvious decrease in crystallite/grain size and enhanced microstrains. Flux jump was observed in low-level doped thin films due to enhanced critical current density by Zr doping. Finally, the vortex phase diagram of δ-Mo0.95Zr0.05N thin films was presented, which will provide guidance for investigation about the vortex mechanisms of δ-Mo1-xZrxN thin films.

Different resistive switching has been observed in the Au/BiFeO3/Pt structure composed with the BiFeO3 (BFO) thin films annealed at different temperature for different dwell time. Resistive switching decreases and disappearances with increasing annealing temperature, while reappear with prolonging dwell time. The evolution in the resistive switching is understand by the polarization modulated interfacial barriers for the low temperature annealing BFO films, oxygen vacancies rectifying interfacial depletion layer barriers for the high temperature and long time, and p-n junction for the films annealed for the longest time at high temperature.