Phase transitions of MnO to 137 GPa
Phase transitions of MnO to 137 GPa
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DOI：
10.1063/1.373045
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发表时间：
2000-04
影响因子：
3.2
通讯作者：
T. Kondo;T. Yagi;Y. Syono;Y. Noguchi;T. Atou;T. Kikegawa;O. Shimomura
中科院分区：
文献类型：
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作者：
T. Kondo;T. Yagi;Y. Syono;Y. Noguchi;T. Atou;T. Kikegawa;O. Shimomura
利用金刚石砧细胞结合同步加速器x射线辐射，在高达137gpa的条件下进行了原位x射线研究，发现了MnO中三个新的相变。B1结构的菱形畸变始于约30gpa。变形相的体积压缩曲线与最近的激波压缩实验结果吻合较好，表明随着Neel温度（TN）的升高，可能出现顺磁-反铁磁转变。在大约90和120 GPa时观察到x射线模式的剧烈变化。90 GPa的过渡压力也与激波压缩数据一致。根据样品的高反射性质，预计高于90 GPa的相为金属。根据最近的第一性原理计算，成功地用B8 （NiAs）结构解释了120 GPa以上高压相的晶体结构。
An in situ x-ray study up to 137 GPa using a diamond anvil cell combined with synchrotron x-ray radiation has revealed three new phase transitions in MnO. The rhombohedral distortion from a B1 structure starts at about 30 GPa. The volume compression curve of the distorted phase is in good agreement with recent shock compression experiments, suggesting the possibility of a paramagnetic–antiferromagnetic transition associated with the increase of the Neel temperature (TN). A drastic change in the x-ray pattern was observed at about 90 and 120 GPa. The transition pressure of 90 GPa is also consistent with shock compression data. The phases above 90 GPa were expected to be metallic based on the highly reflective nature of the sample. The crystal structure of the high pressure phase above 120 GPa was successfully explained by a B8 (NiAs) structure as expected based on recent first principles calculations.