Preparation And Properties Of Rare Earth RFeO₃ And RMnO₃ Thin Films

The perovskite oxide ABO₃ is a strongly correlated electronic system with a complex electronic structure,involving many condensed matter physics issues such as metal-insulator transitions,electronic and magnetic phase separation.Among these oxides,Mn and Fe-based rare earth oxides have become one of the current research hotspots in the field of functional materials and condensed matter physics due to their rich magnetic and optical properties,and outstanding physical and chemical properties and corresponding effects.Based on literature research,a feasible solution method is designed to prepare oxide thin films:Mn₂O₃,Nd₂O₃,Sm₂O₃ and Sm Mn O₃,Sm Fe O₃ and Nd_0.8Sm_0.2Fe O₃ in this paper.Characterize its phase,microstructure,optical properties and magnetic properties,and summarize the research results:(1)X-ray diffraction data indicate that the crystallization of Mn₂O₃?Nd₂O₃?and Sm₂O₃ powders is better when calcined at 575?,800?,and 800?,respectively;(2)Orthogonal Mn₂O₃ and cubic Nd₂O₃,Sm₂O₃ oxide thin films and Sm Mn O₃,Sm Fe O₃,and Nd_0.8Sm_0.2Fe O₃ perovskite oxide thin films were successfully prepared by the solution method.The surface of the thin film sample is continuous and tightly bonded to the substrate.However,except for the Mn₂O₃ thin film which are heat-treated at 180°C and Nd₂O₃,Sm₂O₃ rare earth oxide thin film,;The surface of the thin film sample has a small number of cracks due to the higher heat treatment temperature and the faster rate during the heating process;(3)The absorption spectrum curve of the sample was measured by an ultraviolet-visible spectrophotometer in the experiment.The analysis found that the Mn₂O₃ powder,Mn₂O₃,and Sm Mn O₃ thin film samples all had higher absorption rates in the visible light region,and Mn₂O₃ even had visible light absorption more than 90%;(4)Finally,the room temperature hysteresis loop of the sample was tested with a vibrating sample magnetometer.It was found that except for Mn₂O₃ powder and Nd₂O₃ thin film samples,several other thin film samples exhibited magnetic behavior at room temperature.This is because the shape and size of the thin film sample will cause anisotropy to affect the magnetic structure of the material;in addition,there is an interface effect between the oxide thin film and the substrate,and interfacial oxygen vacancies are formed during the film formation process,which causes the sample at room temperature magnetic behavior.