Electrical polarization switching in bulk single crystal GaFeO$_{3}$

TL;DR

This study investigates electrical polarization switching in GaFeO₃ single crystals, proposing a new atomic displacement model and analyzing the effects of atomic disorder through experiments and calculations.

Contribution

The paper introduces a novel model for polarization switching in GaFeO₃, incorporating atomic disorder effects supported by experimental and computational analysis.

Findings

Demonstrated polarization switching via piezoresponse force microscopy

Measured atomic disorder using X-ray diffraction and Mössbauer spectroscopy

Estimated defect energies and confirmed the proposed switching mechanism

Abstract

The electrical polarization switching on stoichiometric GaFeO$_{3}$ single crystal was measured, and a new model of atomic displacements responsible for the polarization reverse was proposed. The widely adapted mechanism of polarization switching in GaFeO$_{3}$ can be applied to stoichiometric, perfectly ordered crystals. However, the grown single crystals, as well as thin films of Ga-Fe-O, show pronounced atomic disorder. By piezoresponse force microscopy, the electrical polarization switching on a crystal surface perpendicular to the electrical polarization direction was demonstrated. Atomic disorder in the crystal was measured by X-ray diffraction and M\"ossbauer spectroscopy. These measurements were supported by ab initio calculations. By analysis of atomic disorder and electronic structure calculations, the energies of defects of cations in foreign cationic sites were estimated. The energies of the polarization switch were estimated, confirming the proposed mechanism of polarization switching in GaFeO$_{3}$ single crystals.