中国物理B ›› 2007, Vol. 16 ›› Issue (12): 3848-3852.doi: 10.1088/1009-1963/16/12/049
李养贤1, 沈 俊2, 高 博3, 闫丽琴3, 张宏伟3, 胡凤霞3, 孙继荣3
Shen Jun (沈俊)a)b)†, Gao Bo (高博)b), Yan Li-Qin (闫丽琴)b), Li Yang-Xian (李养贤)a), Zhang Hong-Wei (张宏伟)b), Hu Feng-Xia (胡凤霞)b), and Sun Ji-Rong (孙继荣)b)
摘要: Magnetic properties and magnetic entropy changes in LaFe$_{11.5}$Si$_{1.5}$ have been investigated by partially substituting Pr by La. It is found that La$_{1 - x}$Pr$_{x}$Fe$_{11.5}$Si$_{1.5}$ compounds remain cubic NaZn$_{13}$-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$\cdot$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.
中图分类号: (Magnetocaloric effect, magnetic cooling)