MAGNETIC-BEHAVIOR OF NI3P, NI2P, NIP3 AND THE SERIES LN2NI12P7 (LN=PR, ND, SM, GD-LU)

The magnetic properties of the title compounds were investigated with a SQUID magnetometer between 2 K and 300 K. Ni3P, Ni2P, NiP3 and Lu2Ni 12P7 are Pauli paramagnetic. Sm2Ni12P7 shows Van Vleck paramagnetism, while the magnetic susceptibilities of the other ternary phosphides ob ey the Curie-Weiss law resulting in magnetic moments corresponding to the free ion values of the lanthanoid atoms. Thus, the nickel atoms of these ternary phosphides do not carry magnetic moments. The ytterbium atoms in Yb2Ni12P7 show mixed or intermediate valence behaviour. No m agnetic order down to 2 K was observed for the praseodymium, neodymium , holmium, erbium and thulium compound. Gd2Ni12P7 is antiferromagnetic with a Neel temperature of T(N) = 15 K, Dy2Ni12P7 is ferromagnetic (T (C) = 9 K), while Tb2Ni12P7 (T(N) = 12 K) is metamagnetic. The existen ce of EuNi5P3 is confirmed; Eu2Ni12P7 with Zr2Fe12P7-type structure wa s not obtained.