ABSTRACT

The structural transformation of FePO${}_4$ from the trigonal berlinite phase to the orthorhombic CrVO${}_4$ phase has been studied using neutron diffraction at high pressure and high-temperature. The berlinite structure was compressed to a pressure of 5.2(2) GPa and amorphisation observed. Upon annealing at temperatures above 798(28) K the high pressure FePO${}_4$ structure was observed to form. This lowers the formation temperature required to promote this phase over the amorphous phase by ∼100 K compared to previous reports. No other structured phases were observed during the formation process which implies that the CrVO${}_4$ structure is the most stable form at high pressures and is kinetically inhibited from forming at low temperatures.

摘要

FePO的结构转变${}_4$ 从三角硅钙石相到斜方晶CrVO${}_4$已经在高压和高温下使用中子衍射研究了液相。将该berlinite结构压缩至5.2（2）GPa的压力并观察到非晶化。在高于798（28）K的温度下退火后，高压FePO${}_4$观察到形成结构。与以前的报道相比，这将促进该相超过非晶相所需的形成温度降低了约100K。在形成过程中未观察到其他结构相，这表明CrVO${}_4$ 该结构是在高压下最稳定的形式，并且在动力学上抑制了在低温下形成。