Influence of microstructural changes on magnetic refrigeration performance for La(Fe0.94Co0.06)(11.8)Si-1.2 alloys during magnetic field cycling
Influence of microstructural changes on magnetic refrigeration performance for La(Fe0.94Co0.06)(11.8)Si-1.2 alloys during magnetic field cycling
复制标题
磁场循环过程中La(Fe0.94Co0.06)(11.8)Si-1.2合金微观结构变化对磁制冷性能的影响
DOI：
10.1063/1.4906765
复制
发表时间：
2015
影响因子：
3.2
通讯作者：
W J Ren
中科院分区：
文献类型：
--
作者：
Z M Yuan;J He;L Yang;Z J Xia;D L Zhao;C Y You;W J Ren
制备了NaZn_（13）型La（Fe_（0.94）Co_（0.06））_（11.8）Si_（1.2）合金，研究了磁场循环过程中其微观结构变化对磁制冷性能的影响。磁制冷性能测试结果表明，该合金具有较大的磁熵变（ΔS = 14.1 J kg−1 K−1）和最大绝热温变（ΔT = 2.2 K），是一种具有上级磁制冷性能的合金。当循环次数达到1万次时，合金的ΔS和ΔT下降了近10%。超过千次的循环诱发局部应力和晶粒解理，其表现为微裂纹和亚晶界等不可逆微观结构变化的累积。通过对不同循环磁场下合金的磁畴观察发现，这些微观结构特征伴随着局部磁畴的重构和畴壁能量的增加，这可能是导致合金磁畴尺寸减小的原因。
NaZn13-type La(Fe0.94Co0.06)11.8Si1.2 alloys were manufactured to investigate the influence of their microstructural change on magnetic refrigeration performance during magnetic field cycling. The magnetic refrigeration performance measurements indicate that both the large magnetic entropy change value (ΔS = 14.1 J kg−1 K−1) and maximum adiabatic temperature change (ΔT = 2.2 K) are favorable for the alloys to be superior candidate of magnetic refrigerants. However, the alloys exhibit nearly 10% decrease of ΔS and ΔT when they performed cycling ten-thousand times. More than thousand times of cycles induce local stress and grain cleavages presented by the accumulation of irreversible microstructure changes such as micro-cracks and sub-boundaries. According to the domain observation for the alloys with different field cycles, these microstructure characteristics accompany with the reconfiguration of the local magnetic domains and increase of domain wall energy, which are considered to be the reason of the de...