Electronic, magnetic and ferroelectric properties of rhombohedral AgFeO2: an ab initio study

TL;DR

This study uses first-principles density functional theory to explore the electronic, magnetic, and ferroelectric properties of rhombohedral AgFeO2, revealing the role of spin-orbit interaction and noncollinear spins in its behavior.

Contribution

It provides new insights into the magnetic and ferroelectric mechanisms of AgFeO2, highlighting the importance of spin-orbit coupling and lattice effects in its properties.

Findings

Spin-orbit interaction influences magnetic ground state.

Spontaneous polarization arises from noncollinear spin arrangements.

Both electronic and lattice contributions are significant for polarization.

Abstract

Using first principle calculations under the framework of density functional theory we have investigated the electronic structure, magnetism and ferroelectric polarization in the triangular lattice antiferromagnet AgFeO2, and its comparison to the isostructural system CuFeO2. Our calculations reveal that spin orbit interaction plays an important role in determining the magnetic property of AgFeO2 and is possibly responsible for its different magnetic ground state in comparison to CuFeO2. Calculations of ferroelectric polarization of AgFeO2 suggest that the spontaneous polarization arises from noncollinear spin arrangement via spin-orbit coupling. Our calculations also indicate that in addition to electronic contribution, the lattice mediated contribution to the polarization are also important for AgFeO2.