Role of electronic structure and oxygen defects in driving ferromagnetism in nondoped bulk CeO2
Role of electronic structure and oxygen defects in driving ferromagnetism in nondoped bulk CeO2
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DOI：
10.1063/1.3507290
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发表时间：
2010-10
影响因子：
4
通讯作者：
R. Singhal;P. Kumari;A. Samariya;Sudhish Kumar;Subhasini Sharma;Y. Xing;E. Saitovitch
中科院分区：
文献类型：
--
作者：
R. Singhal;P. Kumari;A. Samariya;Sudhish Kumar;Subhasini Sharma;Y. Xing;E. Saitovitch
本文报道了室温铁磁性（RTFM）在非掺杂体氧化铈的可逆操纵。磁化测量结果表明，当在600 °C下真空退火时，顺磁性CeO2被驱动到铁磁状态，而结构没有变化。X射线光电子能谱分析表明，Ce离子从4+态转变为3+态，并伴随着氧空位（VO）的产生. F+中心（单占据氧空位中的电子）在交换机制中起关键作用。该转变显示出完全可逆性，其中通过在空气中重新加热真空退火的CeO2来去除空位来去除RTFM。
This article reports on reversible manipulation of room temperature ferromagnetism (RTFM) in nondoped bulk CeO2. The magnetization measurements establish that paramagnetic CeO2 is driven to a ferromagnetic state, without change in structure, when vacuum annealed at 600 °C. The Ce ions transform from 4+ to 3+ state, accompanied by evolution of oxygen vacancies (VO) during the RTFM transition, as determined by x-ray photoemission. The F+ centers (the electrons in singly occupied oxygen vacancies) play key role in the exchange mechanism. The transition shows complete reversibility where the RTFM is removed by removing the vacancies through re-heating the vacuum-annealed CeO2 in air.