Mfergusonite DyTaO₄under compression: an insight from experiment and theory

Area of Science:

• Materials Science
• Solid State Physics
• Crystallography

Background:

• Dysprosium orthotantalate (DyTaO4) is a rare-earth tantalate with valuable optical, dielectric, and thermal properties.
• Understanding its behavior under extreme conditions is crucial for advanced applications.

Purpose of the Study:

• To synthesize and characterize both M- and M'-type monoclinic phases of DyTaO4.
• To investigate the high-pressure behavior of the M-type DyTaO4 phase using experimental and computational methods.

Main Methods:

• Synchrotron-based X-ray diffraction (XRD) up to ~28 GPa.
• Raman spectroscopy up to ~38 GPa.
• First-principles density functional theory (DFT) calculations.

Main Results:

• Observed a pressure-induced structural phase transition near 24 GPa.
• DFT calculations predicted a transition to a tetragonal structure (P4/nbm) around 15 GPa.
• Anisotropic lattice compression was observed in the low-pressure monoclinic phase (I2/a).
• Determined the bulk modulus for the M-phase and reported Grüneisen parameters.

Conclusions:

• The study provides comprehensive insights into the high-pressure structural evolution of DyTaO4.
• Results contribute to the understanding of pressure effects on rare-earth orthotantalates.