LaFe_(11.5)Si_(1.5)化合物氢化特性及稳定性的研究  

Study on the hydrogenation properties and stability of LaFe_(11.5)Si_(1.5) compound

作　　者：张登魁[1] 赵金良[2] 张红国[1] 岳明[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]北京工业大学应用数理学院,北京100124

出　　处：《物理学报》2014年第19期320-324,共5页Acta Physica Sinica

基　　金：国家自然科学基金青年科学基金(批准号:51301008)和国家自然科学基金(批准号:51071007;51171003)资助的课题~~

摘　　要：系统研究了温度、时间、压力等因素对LaFe11.5Si1.5化合物吸氢过程的影响以及效果.结果表明:吸氢处理会增大化合物的晶格常数,但不会改变其晶体结构.在温度为423 K,氢气压力为0.0987 MPa时,可以制备出氢分布均匀的LaFe11.5Si1.5H1.6间隙化合物.氢化处理可以明显提高化合物的居里温度,降低热滞后,并且使磁熵变保持在较高值.LaFe11.5Si1.5H1.6样品随着在空气中暴露时间的延长,居里温度和磁熵值的变化非常小,氢化合金的磁热性能具有良好的时间稳定性.We have studied systematically the effects of temperature, time, and pressure on the process of hydrogen absorption in LaFe11.5Si1.5compound. Results show that hydrogen absorption can increase the lattice parameter of the compound without changing its crystal structure. The LaFe11.5Si1.5H1.6compound can be prepared at a hydrogen pressure of 0.0987 MPa at 423 K with uniform distribution of hydrogen. Hydrogen absorption can also increase the Curie temperature obviously, decrease the thermal hysteresis and maintain the magnetic entropy change at a high standard. With prolonged exposure time in air, the variation of the Curie temperature and magnetic entropy change of LaFe11.5Si1.5H1.6compound are very small, implying that the magnetic thermal performance of hydride alloy has a good time stability.

关 键 词：P-C-T关系曲线 居里温度 磁熵变 LaFe11.5Si1.5氢化物 

分 类 号：O614.331[理学—无机化学]