A comparative study on magnetic order and field induced magnetic transition on two series of double perovskite iridates RE2BIrO6 (RE=Pr,Nd,Sm,Eu,Gd B=Zn,Mg)

TL;DR

This study compares magnetic properties of two series of double perovskite iridates RE2BIrO6, revealing diverse magnetic behaviors driven by 4f-Ir interactions and field-induced transitions, with implications for understanding complex magnetic states.

Contribution

It provides a comparative analysis of magnetic orders and field-induced transitions in RE2BIrO6 iridates, highlighting the role of 4f-Ir exchange interactions in their magnetism.

Findings

Eu2MgIrO6 shows antiferromagnetic order and spin-flop transitions.

Gd2BIrO6 exhibits contrasting ferromagnetic and antiferromagnetic behaviors.

Pr, Nd, Sm compounds show antiferromagnetic ground states with field-induced transitions.

Abstract

We perform a comparative magnetic study on two series of rare-earth (RE) based double perovskite iridates RE2BIrO6 (RE=Pr,Nd,Sm-Gd;B=Zn,Mg), which show Mott insulating state with tunable charge energy gap from ~330 meV to ~560 meV by changing RE cations. For nonmagnetic RE=Eu cations, Eu2MgIrO6 shows antiferromagnetic (AFM) order and field-induced spin-flop transitions below N\'eel temperature (TN) in comparison with the ferromagnetic (FM)-like behaviors of Eu2ZnIrO6 at low temperatures. For magnetic-moment-containing RE ions, Gd2BIrO6 show contrasting magnetic behaviors with FM-like transition (B=Zn) and AFM order (B=Mg), respectively. While, for RE=Pr, Nd and Sm ions, all members show AFM ground state and field-induced spin-flop transitions below TN irrespective of B=Zn or Mg cations. Moreover, two successive field-induced metamagnetic transitions are observed for RE2ZnIrO6 (RE=Pr,Nd) in high field up to 56 T, the resultant field temperature (H-T) phase diagrams are constructed. The diverse magnetic behaviors in RE2BIrO6 reveal that the 4f-Ir exchange interactions between the RE and Ir sublattices can mediate their magnetism.