Pressure-Induced Spin-State Transition in BiCoO3
Pressure-Induced Spin-State Transition in BiCoO3
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DOI：
10.1021/ja102987d
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发表时间：
2010-07-14
影响因子：
15
通讯作者：
Shimakawa, Yuichi
中科院分区：
文献类型：
--
作者：
Oka, Kengo;Azuma, Masaki;Shimakawa, Yuichi
研究了高压下BiCoO_3的结构和电子性质。同步辐射X射线和中子粉末衍射研究表明，在3 Gpa以上，PbTiO3型结构转变为中心对称的GdFeO3型结构，在室温下体积大幅度下降13%，表现出自旋态的变化。一级相变伴随着电阻率的下降。结构结果表明，Co3+在高压下以低自旋态存在，但X射线发射光谱表明存在中间自旋态。绘制了BiCoO_3的压温相图，估算出BiCoO_3在常压下的转变温度为800-900K。
The structural and electronic properties of BiCoO3 under high pressure have been investigated. Synchrotron X-ray and neutron powder diffraction studies show that the structure changes from a polar PbTiO3 type to a centrosymmetric GdFeO3 type above 3 GPa with a large volume decrease of 13% at room temperature revealing a spin-state change. The first-order transition is accompanied by a drop of electrical resistivity. Structural results show that Co3+ is present in the low spin state at high pressures, but X-ray emission spectra suggest that the intermediate spin state is present. The pressure temperature phase diagram of BiCoO3 has been constructed enabling the transition temperature at ambient pressure to be estimated as 800-900 K.