退火温度对多铁性YFeO_3薄膜的结构、光学及磁学性能的影响

Influence of Annealing Temperature on Structures,Spectroscopic and Magnetic Properties of Multiferroic YFeO_3 Films

采用溶胶–凝胶旋涂法在（111）掺钇氧化锆（YSZ）基片上制备了多铁性YFeO3薄膜,并用X射线衍射仪、原子力显微镜、紫外–可见分光光度计及磁性测量系统,研究了退火温度对YFeO3薄膜的微观结构、光学和磁学性能的影响。结果表明：YFeO3薄膜具有正交钙钛矿的多晶结构,退火温度高于1123K时,薄膜产生了（002）、（311）面的择优取向生长;但当退火温度提高至1223K时,由于再结晶,薄膜晶粒尺寸及表面粗糙度显著增大;YFeO3薄膜在可见光区具有明显的光响应性能,其带隙约为2.21~2.29eV;同时YFeO3薄膜具有室温铁磁性,提高退火温度,样品磁化强度变大,而矫顽力减小。

Multiferroic YFeO3 films were prepared on （111） yttrium stabilized zirconia （YSZ） substrates by a sol-gel spin coating method. The influence of annealing temperature on the micro-structures, optical and magnetic properties of the YFeO3 films was investigated by means of X-ray diffractometer, atomic force microscope, UV-Vis spectrophotometer and superconducting quantum interference device, respectively. The results show that the poly-crystalline YFeO3 films with an orthorhombic perovskite structure are formed. The YFeO3 films show the （002） and （311） preferred orientation growth when the annealing temperature is 〉 1 123 K. The grain size and surface roughness of the film increase obviously when the annealing temperature increases to 1 223 K. The YFeO3 films possess a visible-light response with the energy band gaps between 2.21 and 2.29 eV. In addition, the YFeO3 films also show a ferromagnetic behavior at room temperature. The magnetization of the YFeO3 film increases and the coercive force decreases with the increase of annealing temperature.