Peculiar High-Pressure Behavior of BiMnO3
Peculiar High-Pressure Behavior of BiMnO3
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DOI：
10.1021/ic8015996
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发表时间：
2009-02-02
影响因子：
4.6
通讯作者：
Takayama-Muromachi, Eiji
中科院分区：
文献类型：
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作者：
Belik, Alexei A.;Yusa, Hitoshi;Takayama-Muromachi, Eiji
用同步辐射X射线粉末衍射仪研究了钙钛矿型BiMnO_3的常温高压结构性质。在1.5~5.5 Gpa之间发现了一个具有P2(1)/c对称性的新的单斜相。在8 Gpa以上，正交GdFeO3型相(空间群Pnma)是稳定的。研究了BiMnO_3在8.6GPa室温下的晶体结构(a=5.5132(3)埃，b=7.5752(3)埃，c=5.4535(3)埃)。正交相BiMnO_3具有与LaMnO_3相似的轨道顺序，但在ac平面具有不同的轨道排列。与BiCrO_3和BiScO_3相比，BiMnO_3的高压室温行为不同于常压下的高温行为。这些发现可能为BiMnO_3的研究开辟新的方向。
High-pressure structural properties of perovskite-type BiMnO3 have been investigated by synchrotron X-ray powder diffraction at room temperature. A new monoclinic phase having P2(1)/c symmetry was found between about 1.5 and 5.5 GPa. Above 8 GPa, the orthorhombic GdFeO3-type phase (space group Pnma) is stable. The crystal structure of BiMnO3 at 8.6 GPa and room temperature was investigated (a=5.5132(3) angstrom, b=7.5752(3) angstrom, c=5.4535(3) angstrom). The orthorhombic phase of BiMnO3 has an orbital order similar to LaMnO3 but with a different arrangement of orbitals in the ac plane. High-pressure room-temperature behavior of BiMnO3 differs from high-temperature behavior at ambient pressure in comparison with BiCrO3 and BiScO3. These findings may open new directions in investigation of BiMnO3.