Abstract Multiferroic material bismuth ferrite (BiFeO3 = BFO) and Ho-substitution (Bi1-xHoxFeO3, x = 0.05, 0.10, 0.15, 0.20) thin films were successfully fabricated on silicon (110) substrates by the sol-gel approach. The doping-Ho effects on crystal structure, surface morphology and magnetic property were investigated. The X-ray diffraction (XRD) revealed that the Ho-substitution thin films underwent a phase transition from the rhombohedral to the orthorhombic structure. The changes in Ho-substitution and pure BFO surface appearance were analyzed using the Field Emission Scanning Electron Microscopy (SEM). Meanwhile, the saturation magnetization (Ms) of Ho-substitution samples obtained remarkable augment with the increase in Ho-doping due to the enhancement of superexchange interactions between Fe-O-Fe and spatial modulation for helical structure destruction. The heightening of superexchange interactions is attributed to the reduction of oxygen vacancies because of Ho3+ ions in a stable status.

中文翻译：

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Ho掺杂对溶胶-凝胶技术制备的BiFeO3薄膜晶体结构、表面形貌和磁性能的影响

摘要 通过溶胶-凝胶方法在硅 (110) 衬底上成功制备了多铁性材料铋铁氧体 (BiFeO3 = BFO) 和 Ho 取代 (Bi1-xHoxFeO3, x = 0.05, 0.10, 0.15, 0.20) 薄膜。研究了掺杂-Ho对晶体结构、表面形貌和磁性能的影响。X 射线衍射 (XRD) 显示 Ho 取代薄膜经历了从菱面体到正交结构的相变。使用场发射扫描电子显微镜 (SEM) 分析 Ho 取代和纯 BFO 表面外观的变化。同时，由于 Fe-O-Fe 之间的超交换相互作用和螺旋结构破坏的空间调制的增强，Ho 取代样品的饱和磁化强度 (Ms) 随着 Ho 掺杂的增加而显着增加。由于稳定状态的 Ho3+ 离子，超交换相互作用的增强归因于氧空位的减少。