Errandonea Daniel, Achary Srungarpu N, Diaz-Anichtchenko Daniel, Bandiello Enrico, Marqueño Tomas, Shukla Rakesh, Tyagi Avesh K, Popescu Catalin, Alabarse Frederico G
Departamento de Física Aplicada-ICMUV, MALTA Consolider Team, Universidad de Valencia, Dr. Moliner 50, Burjassot, Valencia 46100, Spain.
Bhabha Atomic Research Centre, Solid State Chemistry Section, Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
Cryst Growth Des. 2023 Feb 28;23(4):2782-2794. doi: 10.1021/acs.cgd.2c01547. eCollection 2023 Apr 5.
We have studied by means of angle-dispersive powder synchrotron X-ray diffraction the structural behavior of KCaPO, SrKPO, and KCe(PO) under high pressure up to 26, 25, and 22 GPa, respectively. For KCaPO, we have also accurately determined the crystal structure under ambient conditions, which differs from the structure previously reported. Arguments supporting our structural determination will be discussed. We have found that KCaPO undergoes a reversible phase transition. The onset of the transition is at 5.6 GPa. It involves a symmetry decrease. The low-pressure phase is described by space group 3̅1 and the high-pressure phase by space group . For KSrPO and KCe(PO), no evidence of phase transitions has been found up to the highest pressure covered by the experiments. For the three compounds, the linear compressibility for the different crystallographic axes and the pressure-volume equation of states are reported and compared with those of other phosphates. The three studied compounds are among the most compressible phosphates. The results of the study improve the knowledge about the high-pressure behavior of complex phosphates.
我们通过角散射粉末同步辐射X射线衍射研究了KCaPO、SrKPO和KCe(PO)在分别高达26、25和22 GPa的高压下的结构行为。对于KCaPO，我们还精确测定了其在环境条件下的晶体结构，该结构与先前报道的结构不同。将讨论支持我们结构测定的论据。我们发现KCaPO经历了可逆的相变。相变起始于5.6 GPa。它涉及对称性降低。低压相由空间群3̅1描述，高压相由空间群 描述。对于KSrPO和KCe(PO)，在实验所涵盖的最高压力下未发现相变迹象。对于这三种化合物，报告了不同晶轴的线性压缩率和压力-体积状态方程，并与其他磷酸盐的进行了比较。所研究的这三种化合物是最易压缩的磷酸盐之一。该研究结果增进了对复杂磷酸盐高压行为的认识。
