Field-induced magnetic ordering in uniaxial nickel systems: A second example

Abstract
The zero‐field susceptibilities parallel and perpendicular to the tetragonal axis of NiCl2⋅4SC(NH2)2 have been measured between 1.2 and 30 K and fitted to the usual spin Hamiltonian. The resulting parameters are D/kB = 7.6±0.4 K, z0J/kB = −4.5±0.3 K, g = 2.26±0.03 and g = 2.34±0.03. The susceptibility has also been measured parallel to the tetragonal axis at constant temperatures between 0.3 and 2 K as a function of external field. Magnetic ordering is found to occur, and portions of the phase boundary between paramagnetic and antiferromagnetic states have been determined.