The electronic structures and magnetic properties of perovskite ruthenates from constrained orbital hybridization calculations

TL;DR

This paper introduces a new method to analyze hybridization effects in perovskite ruthenates, revealing how covalency and pressure influence their electronic structure and magnetic properties.

Contribution

The study develops a constrained orbital hybridization calculation method to clarify how atomic level shifts affect magnetic behavior in ruthenates.

Findings

A covalency between A-site cation and O modifies Ru-O hybridization.

Hydrostatic pressure decreases Ru-O length and band width, reducing magnetic ordering temperature.

Pressure has minimal effect on Ru-O-Ru bond angle in SrRuO₃.

Abstract

We introduce a method to analyze the effect of hybridization by shifting corresponding atomic levels using external potentials. Based on this approach, we study perovskite ruthenates,\ and unambiguously identify that the covalency between the \textit{A}-site cation and O ion will modify the Ru-O hybridization and change the density of state at Fermi level, consequently affect the magnetic properties significantly. We also study the effect of pressure and reveal that hydrostatic pressure has a small effect on the Ru-O-Ru bond angle of SrRuO$_{3}$, while it will decrease the Ru-O length and increase the band width significantly. Therefore, the magnetic ordering temperature will decrease monotonically with pressure.