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Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0≤x≤ 0.5 下载免费PDF全文
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 $T_{\rm C}$ 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. 相似文献