Role of covalency in the ground state properties of perovskite ruthenates: A first principle study using local spin density approximations

TL;DR

This study uses first-principles calculations to explore how covalency influences the electronic and magnetic properties of SrRuO3 and CaRuO3 perovskites, revealing covalency's critical role in their ground states.

Contribution

It provides a detailed first-principles analysis showing covalency's impact on magnetic ground states in ruthenate perovskites, highlighting differences between SrRuO3 and CaRuO3.

Findings

SrRuO3's ferromagnetic ground state matches experiments

CaRuO3 exhibits large spin moments but non-magnetic ground state

Ca-O covalency is key to electronic and magnetic properties

Abstract

We investigate the electronic structure of SrRuO3 and CaRuO3 using full potential linearized augmented plane wave method within the local spin density approximations. The ferromagnetic ground state in SrRuO3 could exactly be described in these calculations and the calculated spin magnetic moment is found to be close to the experimentally observed values. Interestingly, the spin polarized calculations for CaRuO3 exhibit large spin moment as observed in the experiments but the magnetic ground state has higher energy than that in the non-magnetic solution. Various calculations for different structural configurations indicate that Ca-O covalency plays the key role in determining the electronic structure and thereby the magnetic ground state in this system.