High-pressure characterization of multifunctional CrVO₄

Area of Science:

• Materials Science
• Solid State Physics
• Crystallography

Background:

• Understanding the behavior of materials under extreme conditions, such as high pressure, is crucial for developing new technologies.
• Chromium vanadate (CrVO4) is a material with potential applications, but its high-pressure behavior is not fully understood.

Purpose of the Study:

• To investigate the structural stability and physical properties of chromium vanadate (CrVO4) under high pressure up to 10 GPa.
• To elucidate the pressure-induced phase transition mechanism and its impact on material properties.

Main Methods:

• High-pressure x-ray diffraction and Raman spectroscopy were employed to study structural changes.
• Optical absorption and resistivity measurements were conducted to probe electronic and transport properties.
• Ab initio calculations were utilized to support experimental findings and explain observed phenomena.

Main Results:

• A pressure-induced phase transition from the orthorhombic CrVO4-type structure (Cmcm) to a monoclinic wolframite-type structure was observed.
• Significant changes in unit-cell parameters, Raman-active modes, resistivity, and electronic band gap were recorded.
• Vanadium atoms exhibit six-fold coordination in the high-pressure wolframite phase, correlating with volume collapse.

Conclusions:

• The study successfully characterized the high-pressure phase transition in CrVO4, revealing a shift to a wolframite-like structure.
• The observed changes in phonon spectrum, band gap, and resistivity are consistent with the structural transformation and atomic coordination changes.
• First-principles calculations provide a theoretical framework explaining the experimental observations under compression.