Abstract The crystal structure, cryogenic magnetic and magnetocaloric properties in NdFe 2 Si 2 and PrFe 2 Si 2 compounds have been investigated. The NdFe 2 Si 2 and PrFe 2 Si 2 crystallized in the body-centered tetragonal structure with the space group of I4/mmm, and underwent first order magnetic transition from paramagnetic to antiferromagnetic (PM – AFM) around Neel temperatures T N of 8.5 K and 15.5 K, respectively. Under an applied-field change of ΔH = 5 T, the maximum values of magnetic entropy change (−Δ S M max ) are 6.4 J/kg·K and 12.4 J/kg·K for PrFe 2 Si 2 and NdFe 2 Si 2 , corresponding to relative cooling power ( RCP ) values of 0.8 J/cm 3 and 1.0 J/cm 3 , respectively. Moreover, under low applied field change and at low temperatures, the PrFe 2 Si 2 and NdFe 2 Si 2 show an inverse MCE because of the existence of the AFM ordering, while under high external magnetic field change, a normal reversible MCE is observed, which is caused by first-order magnetic transition from antiferromagnetic (AFM) to ferromagnetic (FM) state.

中文翻译：

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研究变磁性 REFe2Si2（RE=Pr 和 Nd）化合物的磁性和磁热特性

摘要 研究了NdFe 2 Si 2 和PrFe 2 Si 2 化合物的晶体结构、低温磁性和磁热性能。NdFe 2 Si 2 和PrFe 2 Si 2 以体心四方结构结晶，空间群为I4/mmm，并在8.5 K的尼尔温度TN附近经历了从顺磁性到反铁磁性（PM-AFM）的一级磁转变。分别为 15.5 K。在 ΔH = 5 T 的外加场变化下，PrFe 2 Si 2 和 NdFe 2 Si 2 的磁熵变最大值 (-Δ SM max ) 分别为 6.4 J/kg·K 和 12.4 J/kg·K，分别对应于 0.8 J/cm 3 和 1.0 J/cm 3 的相对冷却功率 (RCP) 值。此外，在低外加场变化和低温下，由于 AFM 排序的存在，PrFe 2 Si 2 和 NdFe 2 Si 2 显示出逆 MCE，