Magnetic and transport properties of a strongly anisotropic ferromagnet, UCu2P2

We report here the results of the magnetisation and electrical resistivity measurements on UCu2P2 single crystals. This phosphide, crystallizing in the hexagonal structure of CaAl2Si2 type, appears to be a strongly anisotropic ferromagnet with evidence of a significant domain effect at low temperatures. Its Curie temperature is as high as 216 K which is the record for any known ferromagnetic uranium compounds. The anisotropy field is of the order of magnitude of 106Oe. The electrical resistivity results of UCu2P2 undoubtedly point to the semimetallic character of this compound. The character of magnetism in UCu2P2 as well as the origin of its very high Tc are discussed. We present also the magnetic ordering analysis based on the molecular-field approximation. As a result, we found four different magnetic structures which can occur for compounds with the CaAl2Si2-type crystal structure. (author)