Ferromagnetic Mott-Insulating State in Double Perovskites Gd2MgIrO6

TL;DR

This study uses first-principles DFT calculations to reveal that Gd2MgIrO6 is a ferromagnetic Mott insulator with strong Ir-5d and Gd-4f correlations, showing a transition from half-metallic ferromagnetism to insulating behavior.

Contribution

It is the first to demonstrate the ferromagnetic Mott-insulating state in Gd2MgIrO6 driven by strong electron correlations and hybridization effects.

Findings

Gd2MgIrO6 has a ferromagnetic ground state.

The material exhibits a transition from half-metallic ferromagnet to Mott-Hubbard insulator.

Total magnetic moment is 15 μB per formula unit.

Abstract

We have studied the electronic and magnetic properties of double perovskites Gd2MgIrO6 by first-principles density functional theory (DFT). Based on the DFT calculations, Gd2MgIrO6 is found to have a ferromagnetic (FM) ground state. The material undergo half-metallic ferromagnets to Mott-Hubbard insulator transition which happens due to strong correlation in Gd-4f and Ir-5d states. Our results shows that the 5d electrons of Ir hybridize strongly with O-2p states near the Fermi level giving rise to the insulating state of Gd2MgIrO6. Our study suggests that the enhanced magnetic moment is a result of itinerant exchange rather than the exchange interaction involving individual ions of Gd and Ir atoms. The total magnetic moment calculated in the present studies is 15 {\mu}B per formula unit for Gd2MgIrO6.