摘要
The nano-crystalline La_（0.1）Bi_（0.9）FeO_3 compound was successfully synthesized by starch-based combustion method. The crystal structure and magnetic behavior were studied by temperature-dependent X-ray diffraction（XRD）, scanning electron microscopy（SEM）, differential scanning calorimetry（DSC） and magnetic measurements. The La_（0.1）Bi_（0.9）FeO_3 compounds crystallized in a rhombohedrally distorted perovskite structure with space group R3 c. The substitution of La for Bi reduced the rhombohedral distortion. The structural phase transitions in La_（0.1）Bi_（0.9）FeO_3 driven by temperature showed that the extraordinary two-phase coexistence state of BiF eO 3 and LaF eO 3 was observed in a narrow temperature range of 630–700 oC. The magnetization of the La_（0.1）Bi_（0.9）FeO_3 sample was improved by heat treatment in the temperature range. When the heat treatment temperatures rose from 25 to 600 oC, the remanence（Mr） and coercivity（Hc） of the La_（0.1）Bi_（0.9）FeO_3 compound almost remained the same, and increased rapidly to 0.134 emu/g and 7.1 KOe on further increasing the heat treatment temperature to 650 oC.
The nano-crystalline La_（0.1）Bi_（0.9）FeO_3 compound was successfully synthesized by starch-based combustion method. The crystal structure and magnetic behavior were studied by temperature-dependent X-ray diffraction（XRD）, scanning electron microscopy（SEM）, differential scanning calorimetry（DSC） and magnetic measurements. The La_（0.1）Bi_（0.9）FeO_3 compounds crystallized in a rhombohedrally distorted perovskite structure with space group R3 c. The substitution of La for Bi reduced the rhombohedral distortion. The structural phase transitions in La_（0.1）Bi_（0.9）FeO_3 driven by temperature showed that the extraordinary two-phase coexistence state of BiF eO 3 and LaF eO 3 was observed in a narrow temperature range of 630–700 oC. The magnetization of the La_（0.1）Bi_（0.9）FeO_3 sample was improved by heat treatment in the temperature range. When the heat treatment temperatures rose from 25 to 600 oC, the remanence（Mr） and coercivity（Hc） of the La_（0.1）Bi_（0.9）FeO_3 compound almost remained the same, and increased rapidly to 0.134 emu/g and 7.1 KOe on further increasing the heat treatment temperature to 650 oC.
基金
Project supported by the National Natural Science Foundation of China(51161004,51371061,51001033,51401060)
Guangxi Natural Science Foundation(2014GXNSFAA118334)
