CRYSTAL-STRUCTURE AND PROPERTIES OF CUMN3AS2

During an investigation of the Cu-As-Mn system, a new compound with ch emical formula CuMn3As2 and melting point 893 degrees C has been disco vered, and its crystal structure as well as electrical and magnetic pr operties investigated for the first time. The crystal structure of CuM n3As2 is orthorhombic (space group Pnam) with lattice constants a = 1. 3133, b = 0.7352 and c = 0.3823 nm. CuMn3As2 is an antiferromagnet wit h a high Neel temperature T-N = 550 K and an effective magnetic moment mu(eff) = 4.4 mu(B) per Mn ion. The electrical properties of CuMn3As2 are typical of compounds with a mixed conductivity and, at room tempe rature, the specific resistivity and thermoelectric power are equal to 10(-3) Ohm cm and 2 mu V K-1 respectively.