First principles investigations of the electronic and magnetic properties of RVO3 (R = Er, Ho, Y, Lu) vanadates

TL;DR

This study uses ab initio calculations to explore how different rare earth elements affect the electronic and magnetic properties of RVO3 vanadates, revealing insights into their magnetic anisotropy and potential magnetocaloric applications.

Contribution

It provides a detailed theoretical analysis of the electronic structure and magnetic anisotropies of RVO3 compounds with various rare earth elements, highlighting their magnetic behaviors and potential for magnetic cooling.

Findings

Jahn-Teller effect observed with specific band gaps for each compound.

Magnetic anisotropy varies with the rare earth element and influences magnetization directions.

HoVO3 shows a strong exchange coupling and potential for large magnetocaloric effect.

Abstract

In this paper, we investigate the influence of the rare earth element (R) on the physical properties of RVO3 (R = Er, Ho, Y, Lu). For this purpose, a theoretical work is reported in this study using ab initio method with the intent of enhancing our knowledge of the electronic, and magnetic properties of RVO3 (R = Er, Ho, Y, Lu) compounds. The electronic properties of these materials show the presence of Jahn-Teller effect, with a band gap of approximately 0.58eV, 1.57eV, 1.12eV, 1.28eV, for ErVO3, HoVO3, YVO3, LuVO3, respectively. The magnetic contribution of Ho, Er, and V atoms in HoVO3, and ErVO3 compounds was disentangled using X-ray magnetic circular dichroism (XMCD). The magnetic anisotropies of RVO3 with (R = Er, Ho, Y, Lu) are studied and analyzed using spin orbit coupling. We noticed an easy axis of magnetization along the c-direction with strong magneto-crystalline anisotropy energies for the non-magnetic rare earth elements (R = Lu, Y)VO3. For the magnetic rare earth elements, the easy and hard magnetization direction were found to be along b-axis and c-axis, and a- axis and c-axis for HoVO3, and ErVO3, respectively. This means that instead of the standard magnetization demagnetization process, large thermal effects can be obtained by spinning their single crystals in constant magnetic fields. The exchange coupling between (Ho-V) is also found to be greater than the other exchange interactions in HoVO3. Accordingly, a large conventional magnetocaloric effect could be created in HoVO3, since the Ho Ising moments experience a metamagnetic transition. However, the magnetocaloric effect (MCE) is expected to be lower in ErVO3 due to the weak (Er-V) exchange coupling.