Analysis of the magnetic properties of Pr₂Co₁₇ and Nd₂Co₁₇

By means of an improved Hamiltonian, in which the spin-spin dipole interaction is included, some magnetic quantities of the compounds Pr₂Co₁₇ and Nd₂Co₁₇, such as the magnetization, cone angle, etc., have been studied by the conventional parameter-fitting method. It is shown that the calculated results are in agreement with the experimental magnetic data. In particular, the accommodation of the measurements without the spin-spin dipole interaction leads to different values of the second-order crystal field parameter A⁰₂ at different temperatures, a physically undesirable circumstance, and to significant deviations of the calculated cone angles from experiments. These inadequate calculated results of A⁰₂ and θ_c(T) are improved in this paper.