Room-temperature ferromagnetism and ferroelectricity of nanocrystalline La2Ti2O7
Room-temperature ferromagnetism and ferroelectricity of nanocrystalline La2Ti2O7
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DOI：
10.1016/j.jallcom.2010.04.137
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发表时间：
2010-07
影响因子：
6.2
通讯作者：
L. Sun;Jifan Hu;Feng Gao;Xiangwei Kong;H. Qin;M. Jiang
中科院分区：
文献类型：
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作者：
L. Sun;Jifan Hu;Feng Gao;Xiangwei Kong;H. Qin;M. Jiang
采用溶胶-凝胶法制备了La2Ti2O7纳米晶粉末和芯块。纳米晶粉末表现出室温铁磁性。真空退火提高了La2Ti2O7的Fm，表明La2Ti2O7的室温Fm可能来源于纳米颗粒表面及其附近的氧空位。La2Ti2O7球体在1000℃保温1h后，室温下表现出铁磁性和铁电性共存的现象。同时，在La2Ti2O7多铁球体内也观察到了室温磁介电效应，说明了磁电性能之间的耦合。在H=6kOe下，La2Ti2O7多铁球的Δɛr/ɛr(0)在1 kHZ下达到39.3%。
La2Ti2O7nanocrystalline powders and pellets were prepared by sol–gel method. The nanocrystalline powders present room-temperature ferromagnetism (FM). The vacuum annealing enhances FM, showing that the observed room-temperature FM for La2Ti2O7possibly originates from oxygen vacancies at/near surfaces of nanograins. La2Ti2O7pellets annealed at 1000°C for 1h show the coexistence of ferromagnetism and ferroelectricity (FE) at room temperature. Meanwhile, the room-temperature magnetodielectric (MD) effect was also observed in the La2Ti2O7multiferroic pellet, indicating the coupling between magnetic and electric properties. The value of Δɛr/ɛr(0) for La2Ti2O7multiferroic pellet reaches 39.3% at 1kHz under H=6kOe.