本文利用金刚石对顶砧高压技术, 在0.1 MPa~47.5 GPa压力范围内对粒径为8 nm的纳米CeO2进行了高压拉曼光谱研究。研究结果表明, 常压下萤石结构的纳米CeO2(空间群Fm3m)在24.3 GPa时开始发生萤石结构到PbCl2类型(空间群Pnam)的结构相变。这个相变为可逆相变, 卸压至零压时样品恢复至萤石结构。

Raman scattering spectroscopy of nanocrystalline CeO2 with mean particle size of 8 nm was studied under high pressure from 0.1 MPa to 47.5 GPa. A phase transition from fluorite(Fm3m) to PbCl2-type(Pnam) structure was observed at 24.3 GPa. On decompression, the high-pressure phase remained down to 5.2 GPa and then returned to the flourite structure at ambient conditions.