摘要
通过X射线衍射和磁性测量等手段对金属间化合物La0.8Ce0.2(Fe1-xCox)10.5Si2.5(x=0,0.02,0.04,0.06)系的结构、磁性以及磁熵变进行了研究。实验发现,La0.8Ce0.2(Fe1-xCox)10.5Si2.5系的晶体结构均保持立方NaZn13型结构。随着Co含量x的不断增大,晶格常数将单调减小,居里温度TC呈单调增加。当x=0.02时,该化合物在居里温度TC^239 K具有较高的磁熵变︱ΔSM︱,在1 T的磁场下(ΔSM)max为2.87 J.kg-1.K-1。当x=0.04和0.06时,居里温度在室温附近,磁熵变有了一定程度的降低,但仍有可观的磁熵变。最后,对该系列合金作为近室温磁制冷工质的可能性作了适当地探讨。
The crystal structure and magnetic properties of La0.8Ce0.2（Fe1-xCox）10.5Si2.5 were investigated by X-ray powder diffraction and magnetic measurements. X-ray diffraction patterns reveal that the lattice constant decreases and the Curie temperature increases due to the substitution of Co for Fe atoms, while the cubic NaZn13-type maximum value of structure remains unchanged. The maximum value of
｜△SM｜-2.87J·kg^-1·K^-1 under a field of 1 T is achieved in the compound with x = 0.02 at Tc - 239 K. Tc near room temperature in the compound with x = 0.04, 0.06 and the entropy change decreases, however, ｜△SM｜ still have a considerable magnitude. At last, the potential application of La0.8Ce0.2（Fe1-xCox）10.5Si2.5 as a working material for magnetic refrigerants was also discussed.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2005年第6期927-930,共4页
Chinese Journal of Rare Metals
基金
国家自然科学基金资助项目(50164003)
关键词
磁制冷
NaZn13-型金属间化合物
磁熵变
居里温度
稀土
magnetic refrigeration
NaZn13-type intermetallic compounds
magnetic entropy change
Curie temperature
rare earths
