part 8 a
The reason for the violation of the Curie-Weiss law at low temperatures is clearly described in the calculated temperature dependence of the paramagnetic susceptibility, for ErNi5.
Temperature dependence of the paramagnetic susceptibility along the principal directions of the hexagonal ErNi5. The calculated results (lines) fully reproduce experimental data (black points). Violation of the Curie-Weiss law should be noticed at low temperatures.
The origin of so anisotropic behaviour in the externally applied magnetic fields for ErNi5can be balculated the same way.
The high-field magnetization curves at 1.5 K for single crystalline ErNi5 measured along the main hexagonal directions. The calculated results (lines) fully reproduce experimental data (dotted line).
R.J. Radwanski, Z. Ropka & R. Michalski: Magnetism and Electronic Correlations in Local-Moment Systems: Rare Elements and Compounds, edited by M. Donath, P.A. Dowben & W. Nolting, World Scientific (1998) 445-453.