Jinpei Lin1, Zeping Guo1, Mei Li1, Qing Lin1,2, Kangling Huang1, Yun He1,3. 1. 1 College of Physics and Technology, Guangxi Normal University, Guilin, China. 2. 2 College of Medical Informatics, Hainan Medical University, Haikou, China. 3. 3 State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Guangxi Normal University, Guilin, China.
Abstract
BACKGROUND: A multiferroic material can simultaneously show two or more basic magnetic properties, including ferromagnetism, antiferromagnetism, and ferroelectricity. BiFeO3 is a multiferroic material with a rhombohedral distorted perovskite structure. Doping can reduce the volatility of Bi and greatly improve the magnetoelectric properties of BiFeO3. METHODS: To investigate the influence of the doping content we used the following analytical methods: X-ray powder diffraction (XRD), scanning electron microscopy (SEM), microwave network analysis (PNA-N5244A), and the Superconducting Quantum Interference Device (Quantum Design MPMS) test. RESULTS: With the increase of Ca2+ concentration in the solution, the grain size of Bi1- xCa xFeO3 becomes smaller, showing the role of Ca2+ ions as the dopant for fine grains. The calcination temperatures are the major causes for the saturated magnetization. The residual magnetization ( Mr) and the coercive force ( Hc) decrease linearly with the increase of x value, and due to the effect of Ca2+ substitution at Bi3+ sites, which causes the valence change of Fe and/or the oxygen vacancies. CONCLUSIONS: The XRD result indicates that the diffraction peak emerges with the increase of Ca2+ and the main diffraction peak achieves a high angle. The best calcining temperature is 600 °C, and the morphology is very dependent on the calcining temperature.
BACKGROUND: A multiferroic material can simultaneously show two or more basic magnetic properties, including ferromagnetism, antiferromagnetism, and ferroelectricity. BiFeO3 is a multiferroic material with a rhombohedral distorted perovskite structure. Doping can reduce the volatility of Bi and greatly improve the magnetoelectric properties of BiFeO3. METHODS: To investigate the influence of the doping content we used the following analytical methods: X-ray powder diffraction (XRD), scanning electron microscopy (SEM), microwave network analysis (PNA-N5244A), and the Superconducting Quantum Interference Device (Quantum Design MPMS) test. RESULTS: With the increase of Ca2+ concentration in the solution, the grain size of Bi1- xCa xFeO3 becomes smaller, showing the role of Ca2+ ions as the dopant for fine grains. The calcination temperatures are the major causes for the saturated magnetization. The residual magnetization ( Mr) and the coercive force ( Hc) decrease linearly with the increase of x value, and due to the effect of Ca2+ substitution at Bi3+ sites, which causes the valence change of Fe and/or the oxygen vacancies. CONCLUSIONS: The XRD result indicates that the diffraction peak emerges with the increase of Ca2+ and the main diffraction peak achieves a high angle. The best calcining temperature is 600 °C, and the morphology is very dependent on the calcining temperature.
Entities:
Keywords:
BiFeO3; Ca doping; dielectric constant; magnetic; sol-gel; structure