酒井 志朗

<jats:p>A-site-ordered and -disordered GdBaCo<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> films were synthesized through topotactic oxidation. These films exhibit distinct magnetic and conductive properties, attributed to variations in Co spin states driven by changes in ionic arrangement.</jats:p>

<jats:title>Abstract</jats:title><jats:p>The anomalous Hall effect (AHE) that emerges in antiferromagnetic metals shows intriguing physics and offers numerous potential applications. Magnets with a rutile crystal structure have recently received attention as a possible platform for a collinear-antiferromagnetism-induced AHE. RuO<jats:sub>2</jats:sub> is a prototypical candidate material, however the AHE is prohibited at zero field by symmetry because of the high-symmetry [001] direction of the Néel vector at the ground state. Here, we show AHE at zero field in Cr-doped rutile, Ru<jats:sub>0.8</jats:sub>Cr<jats:sub>0.2</jats:sub>O<jats:sub>2</jats:sub>. The magnetization, transport and density functional theory calculations indicate that appropriate doping of Cr at Ru sites reconstructs the collinear antiferromagnetism in RuO<jats:sub>2</jats:sub>, resulting in a rotation of the Néel vector from [001] to [110] while maintaining a collinear antiferromagnetic state. The AHE with vanishing net moment in the Ru<jats:sub>0.8</jats:sub>Cr<jats:sub>0.2</jats:sub>O<jats:sub>2</jats:sub> exhibits an orientation dependence consistent with the [110]-oriented Hall vector. These results demonstrate that material engineering by doping is a useful approach to manipulate AHE in antiferromagnetic metals.</jats:p>