Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0 ≤ x ≤ 0.5
Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0 ≤ x ≤ 0.5
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DOI：
10.1088/1009-1963/16/12/049
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发表时间：
2007-12
期刊：
影响因子：
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通讯作者：
Shen Jun;Gao Bo;Li-Qin Yan;Yang-Xian Li;Hong-wei Zhang;F. Hu;Jirong Sun
中科院分区：
文献类型：
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作者：
Shen Jun;Gao Bo;Li-Qin Yan;Yang-Xian Li;Hong-wei Zhang;F. Hu;Jirong Sun
研究了La部分取代Pr后LaFe_（11.5）Si_（1.5）的磁性能和磁熵变。结果表明，当Pr含量增加到0.5，即x = 0.5时，La_（1-x）Pr_xFe_（11.5）Si_（1.5）化合物仍保持立方NaZn_（13）型结构。Pr取代La导致晶体常数和居里温度的降低。在等温磁化曲线上观察到阶梯状的磁性行为，表明随着Pr含量的增加，TC以上的巡游电子变磁（IEM）转变特征变得更加突出。结果表明，随着磁场从0 T增加到5 T，x从0增加到0.5，磁熵变从23.0 J/kg·K增加到29.4 J/kg·K。更吸引人的是，所有样品的磁熵变在很宽的温度范围内都形成高的平台，这非常有利于埃里克森型磁制冷。
Magnetic properties and magnetic entropy changes in LaFe11.5Si1.5 have been investigated by partially substituting Pr by La. It is found that La1-xPrxFe11.5Si1.5 compounds remain cubic NaZn13-type structures even when the Pr content is increased to 0.5, i.e. x = 0.5. Substitution of Pr for La leads to a reduction in both the crystal constant and the Curie temperature. A stepwise magnetic behaviour in the isothermal magnetization curves is observed, indicating that the characteristic of the itinerant electron metamagnetic (IEM) transition above TC becomes more prominent with the Pr content increasing. As a result, the magnetic entropy change is remarkably enhanced from 23.0 to 29.4 J/kg·K as the field changes from 0 to 5 T, with the value of x increasing from 0 to 0.5. It is more attractive that the magnetic entropy changes for all samples are shaped into high plateaus in a wide range of temperature, which is highly favourable for Ericsson-type magnetic refrigeration.