| In transition metal oxide materials,the interaction between electrons is strong and there are a complex and delicate coexistence and competition among charge,spin,orbit and lattice degrees of freedom,resulting in a variety of ordered phases and abundant phase transitions.These phase transitions are often accompanied with great changes in macroscopic physical properties,resulting in novel phenomena and extraordinary properties.The complex phase diagram and delicate phase balance make the physical properties of transition metal oxide materials unusually sensitive to the applied electric field,magnetic field,stress and temperature,which provides an opportunity for the development of new magnetic and electrical information devices and their principles.Applications of micromodule often require high quality of thin film materials.Therefore,it is of great significance to realize superb epitaxy of functional oxide materials and further explore its novel magnetic and electrical properties and physical and chemical mechanisms behind.These will promote applications of functional oxide materials in sensor,storage as well as in other fields.This paper systematically studied the technological parameters of pulsed laser deposition during the preparation of barium titanate,lead zirconate titanate and ferroferric oxide on perovskite,silicon and mica substrate.Further characterizations of ferroelectricity in lead zirconate titanate thin films grown on the different substrates were researched.Moreover,using micro-fabrication technique,the artificial structure of edge states in ferroferric oxide films was obtained and its magnetoelectricity properties were characterized in this paper.In this paper,by changing the laser energy,oxygen pressure,distance between the substrate and target,as well as the temperature of the substrate during pulsed laser deposition,the process parameters of growing Pb(Zr0.1Ti0.9)O3 and SrRuO3 thin films on the surface of(001)SrTiO3 and(011)DyScO3 single crystal substrate were systematically studied and the films with atom-scale flat suface were obtained.Electrical measurements showed that the ferroelectric properties of Pb(Zr0.1Ti0.9)O3 films are good.It was found that the ferroelectric domain structure of Pb(Zr0.1Ti0.9)O3 films grown on DyScO3 substrate changed orderly from c-type domains to a/c-type domains with the increase of film thickness.The reason is that while the films became thicker,the elastic energy was raised,and the film released some of this energy by forming a multiple ferroelectric domains.In terms of silicon-based perovskite oxide epitaxy,this paper studied and optimized the wet-chemical treatment of Si surface and the process parameters of importing SrO buffer layer in the pulsed laser deposition technology.We proposed and attempted for the first time to introduce SrO and Sr3Al2O6 multi buffer layered structure on Si surface to grow perovskite materials.SiO2 on Si surface was successfully removed in the experiment.By introducing SrO and Sr3Al2O6 buffer layer on Si surface for structural transition and inhibiting interfacial diffusion,the silicon-based epitaxial growth of perovskite oxides was realized,and silicon-based Pb(Zr0.1Ti0.9)O3 films with observable ferroelectric properties were obtained.It is found that the ferroelectric domain structure of silicon-based Pb(Zr0.1Ti0.9)O3 films’ domains were irregularly distributed,which was caused by its disordered crystal structure.By using pulsed laser deposition technique,the effect of substrate temperature on crystalline quality and oxygen pressure on electronic structure of Fe3O4 films grown on mica substrate was systematically studied.The magnetic and electrical properties at the edge of Fe3O4 films were studied by the measurements of MFM and C-AFM.It is found that the resistance of Fe3O4 films at the edge was much smaller than that inside by two orders of magnitude,and the shape of magnetic domain appearing like a strip was also different from that inside,which was droplet shaped.This phenomenon needs further study. |
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