中文摘要：

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。

英文摘要：

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.