High-pressure single-crystal X-ray diffraction study of ErVO4

TL;DR

This study investigates the structural changes of ErVO4 under high pressure using single-crystal X-ray diffraction, revealing a zircon-to-scheelite phase transition at 7.9 GPa and providing detailed pressure-dependent structural data.

Contribution

The paper provides the first detailed high-pressure structural analysis of ErVO4, including precise measurements of phase transition pressure and elastic properties, challenging previous reports of phase coexistence.

Findings

Zircon to scheelite transition at 7.9 GPa

No phase coexistence or additional transitions below 20 GPa

Accurate pressure dependence of unit-cell parameters and volume

Abstract

We present an investigation into the crystal structure of ErVO4 under variable pressure conditions. The high-pressure single crystal X-ray diffraction experiments performed employing helium as the pressure medium facilitated structure refinements up to 24.1(2) GPa. The transition from zircon to scheelite was observed at a pressure of 7.9(1) GPa. In contrast to previous reports, we did not detect any sign of phase coexistence. We also did not observe the second phase transitions previously predicted by density-functional theory to occur below 20 GPa. The determination of the pressure dependence of unit-cell parameters and volume yields precise values for linear compressibility of each axis and the pressure-volume equation of state for both the zircon and scheelite phases. Additional information on the mechanical properties of ErVO4, obtained from density-functional theory calculations, is also reported.