磁制冷
锰铁矿
凝聚态物理
铁磁性
反铁磁性
充电顺序
顺磁性
材料科学
制冷剂
电荷(物理)
相变
大气温度范围
磁化
磁场
热力学
物理
量子力学
气体压缩机
作者
N. S. Bingham,Manh‐Huong Phan,H. Srikanth,M. A. Torija,Chris Leighton
摘要
The influence of first- and second-order magnetic phase transitions on the magnetocaloric effect (MCE) and refrigerant capacity (RC) of charge-ordered Pr0.5Sr0.5MnO3 has been investigated. The system undergoes a paramagnetic to ferromagnetic transition at TC∼255 K followed by a ferromagnetic charge-disordered to antiferromagnetic charge-ordered transition at TCO∼165 K. While the first-order magnetic transition (FOMT) at TCO induces a larger MCE (6.8 J/kg K) limited to a narrower temperature range resulting in a smaller RC (168 J/kg), the second-order magnetic transition at TC induces a smaller MCE (3.2 J/kg K) but spreads over a broader temperature range resulting in a larger RC (215 J/kg). In addition, large magnetic and thermal hysteretic losses associated with the FOMT below TCO are detrimental to an efficient magnetic RC, whereas these effects are negligible below TC because of the second-order nature of this transition. These results are of practical importance in assessing the usefulness of charge-ordered manganite materials for active magnetic refrigeration, and Pr0.5Sr0.5MnO3 provides an interesting case study in which the influence of first- and second-order transitions on MCE could be compared in the same system in a single experiment.
科研通智能强力驱动
Strongly Powered by AbleSci AI