PrNi$lt;sub$gt;2$lt;/sub$gt;的磁和磁热性能研究

在一些磁性材料内, 磁性离子间交换作用和磁性离子的自旋涨落对材料磁性有影响. 本文根据磁比热实验值确定了晶场参数后, 利用包含自旋涨落的交换作用有效场H_m= n₀ (1 + γ T + β e^{ω T})M, 计算了PrNi₂晶体晶场能级的Zeeman劈裂. 在温度为3.8 K ≤T≤ 30 K范围内, 计算了该晶体多晶磁矩随外磁场的变化, 以及外磁场H=5000 Oe时磁化率倒数随温度的变化, 计算结果和实验值符合较好. 当外磁场在0–50000 Oe时, 计算的该晶体的磁熵变与已有文献的理论结果相似. 计算结果说明, 提出的包含自旋涨落的交换作用有效场不仅适合亚铁磁性晶体, 而且也适合顺磁性晶体. 关键词： 2')" href="#">PrNi₂ 磁比热 交换作用有效场 磁矩 磁熵变

Investigation on the magnetic and magneto caloric prop erties of PrNi2

The magnetic properties of some magnetic materials are influenced by the exchange interaction between magnetic ions and the spin fluctuations of magnetic ions. By use of the exchange interaction-effective field including the spin fluctuations of magnetic ions H_m= n₀(1+γ T +β e^{ω T})M, the Zeeman splitting of crystal field energy levels of Pr³⁺ ions in PrNi₂ and the variation of the magnetic moments with the applied field in a temperature range of 3.8 K≤ T ≤ 30 K are calculated. The thermal variation of the reciprocal susceptibility of Pr³⁺ ions is calculated as well for the applied magnetic field H=5000 Oe. The calculated results are in good agreement with the experimental data. The magnetic entropy changes are obtained theoretically in a magnetic field range of 0<H<50000 Oe, and the results are similar to those reported in the literature. It is indicated that the exchange interaction-effective field containing the spin fluctuations is applicable not only to the ferrimagnetic crystals, but also to the paramagnets.
Keywords： 2')" href="#">PrNi₂ magnetic specific heat exchange interaction-effective field magnetic moment magnetic entropy change