We report on a theoretical and experimental study of CuMn-V antiferromagnets. Previous works showed low-temperature antiferomagnetism and semimetal electronic structure of the semi-Heusler CuMnSb. In this paper we present theoretical predictions of high-temperature antiferromagnetism in the stable orthorhombic phases of CuMnAs and CuMnP. The electronic structure of CuMnAs is at the transition from a semimetal to a semiconductor and we predict that CuMnP is a semiconductor. We show that the transition to a semiconductor-like band structure upon introducing the lighter group-V elements is present in both the metastable semi-Heusler and the stable orthorhombic crystal structures. On the other hand, the orthorhombic phase is crucial for the high N\'eel temperature. Results of X-ray diffraction, magnetization, transport, and neutron diffraction measurements we performed on chemically synthesized CuMnAs are consistent with the theory predictions.
@article{arxiv.1102.5373,
title = {CuMn-V compounds: a transition from semimetal low-temperature to semiconductor high-temperature antiferromagnets},
author = {F. Maca and J. Masek and O. Stelmakhovych and X. Marti and K. Uhlirova and P. Beran and H. Reichlova and P. Wadley and V. Novak and T. Jungwirth},
journal= {arXiv preprint arXiv:1102.5373},
year = {2011}
}