Room-temperature antiferromagnetism in CuMnAs

We report on an experimental and theoretical study of CuMn–V compounds. In agreement with previous works we find low-temperature antiferromagnetism with Néel temperature of 50K in the cubic half-Heusler CuMnSb. We demonstrate that the orthorhombic CuMnAs is a room-temperature antiferromagnet. Our results are based on X-ray diffraction, magnetization, transport, and differential thermal analysis measurements, and on density-functional theory calculations of the magnetic structure of CuMn–V compounds. In the discussion part of the paper we make a prediction, based on our density-functional theory calculations, that the electronic structure of CuMn–V compounds makes a transition from a semimetal to a semiconductor upon introducing the lighter group-V elements. ► We report experimental observation of high temperature antiferromagnetism in CuMnAs. ► The physical origin of the observation is discussed based on ab initio calculations. ► We predict semimetal to semiconductor transition of the electronic structure of CuMn–V compounds. ► We discuss the relevance of CuMn–V compounds for antiferromagnetic spintronics.