Magnetic and Electrical Properties of Ni(As_xS_1-x)₂

Abstract

Magnetic, electrical and structural properties of Ni(As x S 1- x ) 2 for 0≤ x ≤0.5 were investigated experimentally. The magnetic transition points, Néel and Curie points, and the metallic and nonmetallic regions were determined as a function of concentration and temperature. The critical concentration for the magnetic and electrical transitions at absolute zero was given to be x =0.22. The phase diagram thus obtained can be interpreted qualitatively by the Hubbard model, in which the parameters of transfer integral, Coulombs' correlation and electron numbers in e g band are contained. Furthermore, the behavior of electrical resistivity can be explained by the spin fluctuation theory. Finally, a general view of the phase diagram of solid solutions among pyrite type compounds is summarized from the same standpoint.