放氢温度对吸氢后La_(1-x)Ce_xFe_(11.44)Si_(1.56)合金磁热性能的影响  

Effects of Insulation Temperature on Magnetocaloric Properties of La_(1-x)Ce_xFe_(11.44)Si_(1.56) Alloy after Hydrogen Absorption

作　　者：夏伟[1,2] 黄焦宏[1] 刘翠兰[1] 松林[2] 张文佳[1,3] 特古斯[2] 

机构地区：[1]包头稀土研究院,内蒙古包头014030 [2]内蒙古师范大学内蒙古自治区功能材料物理与化学重点实验室,内蒙古呼和浩特010022 [3]内蒙古科技大学材料与冶金学院,内蒙古包头014010

出　　处：《稀土》2016年第3期50-55,共6页Chinese Rare Earths

基　　金：国家自然科学基金项目(51261001);国际合作项目(2011DFA53230)

摘　　要：利用X射线衍射仪(XRD)和VSM测量La_(1-x)Ce_xFe_(11.44)Si_(1.56)合金吸氢前后的相结构及磁性曲线,利用DSC测量了La_(0.8)Ce_(0.2)Fe_(11.44)Si_(1.56)Hy的热重曲线。结果表明,La_(1-x)Ce_xFe_(11.44)Si_(1.56)合金及其氢化物的主相均为NaZn_(13)型立方结构,吸氢后合金的居里温度明显升高,在室温空气中放置一段时间后,仍能保持良好的稳定性;La_(0.8)Ce_(0.2)Fe_(11.44)Si_(1.56)Hy合金约从483 K到708 K一直处于失重状态,氢化物的失重率为0.19%;通过提高放氢温度,La_(0.9)Ce_(0.1)Fe_(11.44)Si_(1.56)Hy合金的居里温度降低,放氢温度每提高10 K居里温度下降10 K左右,但对合金的等温磁熵变影响很小,熵变最小的样品与无放氢样品的熵变相差仅0.616 J/(kg·K)。The phase structure and magnetic curves of La1-x Cex Fe11. 44 Si1. 56 alloy and its hydrides were detected by X -ray diffraction （XRD） and vibrating sample magnetometer （ VSM）, and the DSC was used to measure the thermogravimetric curve of La0.8Ce0.2Fe11.44Si1.56Hy.The results show that La1-xCexFe11.44Si1.56 and its hydride alloy are composed of the NaZn13 - type phase, and after Hydrogen absorption the curie temperature of alloy rises significantly, and alloys remaine fine stable on staying in air at room temperature after a period of time; The La0.8Ce0.2Fe11.44Si1.56Hy alloy has been in a state of weightlessness from 483 K to 708K, by the calculation the percentage of weighelessness of hydride is 0.19% ; By raising the temperature of hydrogen desorption, the Curie temperature of La0.9 C e0.1 Fen.44 Sit. 56 Hy alloy decreases, hydrogen desorption temperature increases 10 K and the Curie temperature decreases 10K, but effect of isothermal magnetic entropy change of the alloy is very little, the entropy change between minimum entropy change of samples and no hydrogen samples are only 0. 616 J/（ kg·K）.

关 键 词：放氢温度 居里温度 等温磁熵变 La1-xCexFe11.44Si1.56Hy 

分 类 号：TG132.27[一般工业技术—材料科学与工程] TM271[金属学及工艺—合金]