Effect of Ho substitution on structure and magnetic property of BiFeO3 prepared by sol–gel method

Abstract

We report the effect of the variation of concentration on the structure and magnetic property of the Ho doped BiFeO3 (Bi1−xHoxFeO3, x=0, 0.05, 0.1, 0.15 and 0.2) thin films. The result shows that all the peaks for BiFeO3, Bi0.95Ho0.05FeO3 and Bi0.9Ho0.1FeO3 thin films can be indexed according to the crystal structure of pure BiFeO3 by X-ray diffraction. A structural transition from the rhombohedral to orthorhombic occurred in the film with Bi0.85Ho 0.15FeO3 and Bi0.8Ho0.2FeO3. Raman spectroscopy indicates the substitution of Ho into the Bi site in BiFeO3 thin films. Scanning electron microscope and Transmission electron microscope are used to analyze the morphology and micro-structures of the thin films. The actual distribution can be easily observed in Energy-dispersive spectrometry elemental mappings. In comparison with the BiFeO3 thin film studies here, the Bi0.9H0.1FeO3 thin film shows the surprising remnant magnetization and saturation magnetization. The remnant magnetization of Bi0.9H0.1FeO3 thin film is nearly 8 times as large as that of BiFeO3 thin film. Moreover, the possible reasons for the enhancement of magnetization are discussed in detail.