Chiral Ruthenium Halide Semiconductor with Strong Antiferromagnetic Coupling

Abstract

Chiral hybrid organic–inorganic metal halides have attracted wide attention owing to their superior chiroptoelectronic and chirospintronic properties. Here, a new class of chiral lead-free metal halides, (R/S-MBA)3Ru2Br9 (MBA = methylbenzylammonium), with unique magnetic properties is reported. (R/S-MBA)3Ru2Br9 is composed of a surface-shared octahedron dimer separated by chiral cations and crystallizes into the Sohncke space group of P212121. The crystal structures, chiroptical, magnetic properties, and magnetic circular dichroism of (R/S-MBA)3Ru2Br9 are systematically investigated. Owing to the strong antiferromagnetic coupling between the Ru atom through bromine bridge in the [Ru2Br9]3− dimer and the weak ferromagnetic coupling between the neighboring [Ru2Br9]3− dimer, (R/S-MBA)3Ru2Br9 exhibits antiferromagnetic property with Néel temperature at 7 K. Considering the unique magnetic property of ruthenium, together with the rapid progress of antiferromagnetic spintronics and optospintronics recently, this work provides a novel multifunctional lead-free chiral magnetic candidate toward chiral optoelectronics and antiferromagnetic spintronics.