摘要
LaFe11.5Si1.5By(y=0,0.1,0.2,0.3,0.4和0.5)系列合金,通过添加少量的B后,可以明显的缩短退火时间。晶格常数随着B含量的增加而逐渐增大。居里温度随着B的增加分别从183K升高到186K。该系列化合物的热滞很小,B的添加对其热滞几乎没有影响。在外加磁场变化为0~1.5T时,等温磁熵变的最大值从20.0J/kgK(y=O)逐渐下降到10.7J/kgK(y=0.5)。该系列化合物在B含量较低时,处于居里温度(R)之上则存在比较明显的场致变磁转变特性。随着B含量增加到0.5时,场致变磁转变特性明显减弱。
The annealing time of LaFe11.5Si1.5By(y = 0, 0. 1, 0.2, 0.3, 0.4 and 0.5) alloys can be reduced obvious ly by introducing interstitial atom B. The lattice parameter slightly increases with increasing B content. By changing the boron concentration from 0 to 0.5, the Curie temperature (Tc) increases from 183 to 186 K. It can be seen that there is a small thermal hysteresis between heating and cooling curves for these compounds, but the thermal hystere- sis is not affected by B addition. The maximal magnetic entropy change decreases from 20. 0 to 10.7 J/kgK by chan- ging y from 0 to 0. 5. It is obvious that the itinerant electron metamagnetic (IEM) transition is observed for Iow B content above the Curie temperature. The IEM transition disappears when y increase to 0. 5.
出处
《金属功能材料》
CAS
2010年第1期22-26,共5页
Metallic Functional Materials
基金
国家自然科学基金资助项目(50661004)
内蒙古科技计划项目(20070402)
黄山学院自然科学项目(2008xkjq010)
关键词
磁熵变
磁热效应
金属间合金
场致变磁转变
稀土
magnetocaloric effect
magnetic entropy change
intermetallic alloy
itinerant electron metamagnetic transition
rare earths