Electronic structure, magnetism, and optical properties of orthorhombic GdFeO3 from first principles

TL;DR

This study uses first-principles calculations to analyze the electronic, magnetic, and optical properties of orthorhombic GdFeO3, revealing its stable magnetic phase, accurate band gap, and optical characteristics, with implications for similar materials.

Contribution

It provides a comprehensive first-principles analysis of GdFeO3's properties using the mBJ potential, improving understanding of its electronic structure and magnetism compared to previous studies.

Findings

G-AFM is the stable magnetic phase of GdFeO3.

Calculated band gap with mBJ matches experimental values.

Optical properties and dielectric functions are characterized accurately.

Abstract

Orthorhombic GdFeO$_3$ has attracted considerable attention in recent years because its magnetic structure is similar to that in the well-known BiFeO$_3$ material. We investigate electronic structure, magnetism, and optical properties of the orthorhombic GdFeO$_3$ in terms of density-functional-theory calculations. The modified Becke-Johnson (mBJ) exchange potential is adopted to improve on the description of the electronic structure. Our calculation show that the G-type antiferromagnetic (G-AFM ordering of Fe spins) phase of orthorhombic GdFeO$_3$ is stable compared to other magnetic phases. The semiconductor gap calculated with mBJ, substantially larger than that with GGA, is in good agreement with recent experimental values. Besides, we also investigate effect of the spin-orbit coupling on the electronic structure, and calculate with mBJ the complex dielectric functions and other optical functions of photon energy. The magnetic exchange interactions are also investigated, which gives a Neel temperature close to experimental observation. For comparison towards supporting our results, we study the electronic structure of rhombohedral (R3c) BiFeO$_3$ with mBJ. These lead to a satisfactory theoretical understanding of the electronic structure, magnetism, and optical properties of orthorhombic GdFeO$_3$ and can help elucidate electronic structures and optical properties of other similar materials.