High-Pressure Induced Structural Phase Transition in CaCrO4: Evidence from Raman Scattering Studies

TL;DR

This study investigates the structural phase transition of CaCrO4 under high pressure using Raman scattering, revealing a reversible transition from zircon to scheelite structure around 6-10 GPa and its quenchability to ambient conditions.

Contribution

It provides the first detailed Raman spectroscopic analysis of CaCrO4's pressure-induced phase transition and identifies the structural change from zircon to scheelite type.

Findings

Structural transition begins near 6 GPa and completes around 10 GPa.

High-pressure phase can be quenched to ambient conditions.

Identified the transition as from zircon-type to scheelite-type structure.

Abstract

Raman spectroscopic studies have been carried out on CaCrO4 under pressure up to 26GPa at ambient temperature. The Raman spectra showed CaCrO4 experienced a continuous structural phase transition started at near 6GPa, and finished at about 10GPa. It is found that the high-pressure phase could be quenched to ambient conditions. Pressure dependence of the Raman peaks suggested there existed four pressure regions related to different structural characters. We discussed these characters and inferred that the nonreversible structural transition in CaCrO4, most likely was from a zircon-type (I41/amd) ambient phase to a scheelite-type high pressure structure (I41/a).