Unusual magnetic behavior of cubic double perovskite Ba₂YIrO₆ with Ir⁵⁺(5d⁴) ions

¹ School of Physics, Hangzhou Normal University, Hangzhou - Zhejiang, 311121, China
² Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences Hefei, 230031, China
³ Science Island Branch of Graduate School, University of Science and Technology of China - Hefei, 230026, China

Received: 10 December 2023
Accepted: 23 January 2024

Abstract

Using density functional calculations, we investigate the electronic structure and magnetism of double-perovskite Ba₂YIrO₆ to explore the origin of its unusual magnetic behavior. Our results show that the breakdown of expected j = 0 nonmagnetic state of Ir⁵⁺(5d⁴) in Ba₂YIrO₆ is induced by both bandwidth and exchange interaction. In addition, the bandwidth effect makes the system behave like metal, while the antiferromagnetic interaction between Ir ions should be responsible for the insulator behavior. Moreover, the strong geometrical frustration in Ir triangular unit prevents the formation of long-range magnetic order.