The Nd-Cu-P system

Phase equilibria were established in the isothermal sections at 670 K and 8 70 K of the Nd-Cu-P ternary system up to 75 at.% P and in the region of 0-2 5 at.% P,respectively. The isothermal sections have been obtained from X-ra y diffraction data. The existence of the ternary phosphides NdCu3.8P2 and N d5Cu17.8P12 has been confirmed. Two new phosphides NdCu4P2 and NdCuP2 have been obtained. The crystal structure of NdCuP2 has tetragonal symmetry (tet ragonal body-centered unit cell: a = 3.9021(3), c = 19.601(2) Angstrom). Th e crystal structure of the NdCu4P2 has been refined from X-ray powder diffr action data: space group Pmmn, SmNi4P2 type structure, a = 14.6746(8), b = 11.0027(6), c = 3.9045(2) Angstrom, z = 6, R-1 = 0.083). Structure peculiar ities of the NdCu4P2 phosphide and relationships with known structure types are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.