摘要
La0.5Ca0.5MnO3块体陶瓷表现出电荷有序态特性,但是当La0.5Ca0.5MnO3颗粒减小后电荷有序态将被破坏.本文采用磁测量法研究了La0.5Ca0.5MnO3纳米颗粒的铁磁相变临界行为.结果表明La0.5Ca0.5MnO3纳米颗粒的铁磁相变临界行为可用平均场模型很好地拟合,意味着La0.5Ca0.5MnO3纳米颗粒的铁磁相变为长程有序作用特征.输运行为表明,外加磁场可诱导La0.5Ca0.5MnO3纳米颗粒产生绝缘体-金属转变,可归因于外加磁场使得晶界势垒降低所致.
Critical behavior of ferromagnetic transition in 30 nm-sized La0.5Ca0.5MnO3 nanoparticle is studied using magnetization methods. The results show that charge order state is fully destabilized due to the surface pressure, and the critical behavior of the derived La0.5Ca0.5MnO3 nanoparticle can be classified into mean-field theory model, implying long-range ferromagnetic interaction. No insulator-metal transition is observed under zero field due to the grain size effects. With increasing magnetic field, insulator-metal transition is induced.
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2014年第11期1181-1186,共6页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金资助项目(批准号:11104001)
