paper

Absence of itinerant ferromagnetism in a cobalt-based oxypnictide

arXiv:2409.06337 · doi:10.1103/PhysRevMaterials.8.094405

Abstract

We report a layered transition-metal-ordered oxypnictide Sr $_{2}$ CrCoAsO $_{3}$ . The new material was synthesized by solid-state reactions under vacuum. It has an intergrowth structure with a perovskite-like Sr $_{3}$ Cr $_{2}$ O $_{6}$ unit and ThCr $_{2}$ Si $_{2}$ -type SrCo $_{2}$ As $_{2}$ block stacking coherently along the crystallographic $c$ axis. The measurements of electrical resistivity, magnetic susceptibility, and specific heat indicate metallic conductivity from the CoAs layers and short-range antiferromagnetic ordering in the CrO $_{2}$ planes. No itinerant-electron ferromagnetism expected in CoAs layers is observed. This result, combined with the first-principles calculations and the previous reports of other CoAs-layer-based materials, suggests that the Co $-$ Co bondlength plays a crucial role in the emergence of itinerant ferromagnetism.

9 pages, 7 figures