Bastnaesite (Ce0.50La0.25Nd0.20Pr0.05)CO3F is an interesting pattern family of (CO3)2− and F− co-existing phases, which is a meaningful sample to study the influence of multiple volatiles on minerals. Thermal stability of bastnaesite has been investigated by thermogravimetric experiment and in situ high-temperature Raman. The results demonstrate that bastnaesite undergoes a decarbonization transition at above 673 K. The isobaric-mode Grüneisen parameters range from 0.04 to 2.28. The compressibility of bastnaesite has been investigated by synchrotron radiation X-ray diffraction and Raman spectroscopy combined with diamond anvil cells up to 19.2 GPa at room temperature. Isothermal pressure–volume relationship of bastnaesite is fitted to the second-order Birch–Murnaghan equation of state with V0 = 430.87(3) Å3, K0 = 118.35(1) GPa. Its axial compressibility presents anisotropic, attributed to the rigid (CO3)2− group parallel to c-axis. Its isothermal-mode Grüneisen parameters and intrinsic anharmonic-mode parameters range from 0.23 to 1.91 and− 3.5 × 10−5 K−1 to 0.82 × 10−5 K−1, respectively. The presence of F− can largely enhance the thermal stability and incompressibility of minerals.

中文翻译：

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氟碳铈矿的热稳定性和压缩性

氟碳铈矿 (Ce0.50La0.25Nd0.20Pr0.05)CO3F 是一个有趣的 (CO3)2- 和 F- 共存相模式族，是研究多种挥发物对矿物影响的有意义的样本。通过热重实验和原位高温拉曼光谱研究了氟碳铈矿的热稳定性。结果表明氟碳铈矿在 673 K 以上经历脱碳转变。等压模式 Grüneisen 参数范围为 0.04 至 2.28。已通过同步辐射 X 射线衍射和拉曼光谱结合金刚石砧室在室温下研究了氟碳铈矿的可压缩性，最高可达 19.2 GPa。氟碳铈矿的等温压力-体积关系符合二阶 Birch-Murnaghan 状态方程，其中 V0 = 430.87(3) Å3，K0 = 118.35(1) GPa。其轴向压缩性呈现各向异性，归因于平行于 c 轴的刚性 (CO3)2- 基团。其等温模式 Grüneisen 参数和固有非谐波模式参数范围分别为 0.23 到 1.91 和− 3.5 × 10−5 K−1 到 0.82 × 10−5 K−1。F-的存在可以大大提高矿物的热稳定性和不可压缩性。