LaFe11.2Co07Si11合金在室温区的巨大磁熵变

Very large magnetic entropy change near room temperature in LaFe11.2Co07Si11

摘要: 在具有立方NaZn13型结构的稀土铁基化合物LaFe11.2Co07Si11中发现室温区的巨大磁熵变，磁熵变的峰值位于居里温度TC=274K处，5T外磁场下达到～203J/kg K，约为相同的温区下金属Gd的2倍.LaFe11.2Co07Si11合金中强烈的磁弹性耦合，导致晶格在居里温度处出现巨大负膨胀，这是其巨大磁熵变的来源.
- NaZn13型金属间化合物 /
- 晶格巨大负膨胀 /
- 磁熵变
Abstract: Very large magnetic entropy change has been observed in the Fe-based cubic NaZn13-type compound LaFe11.2Co07Si11near the Curie temperature TC of 274K. The value of this change is ～20.3J/kg K under a magnetic field of 5T at TC=274K， which markedly exceeds that of pure Gd by a factor of 2 in the corresponding temperature range. The strong structural and magnetic interplay in the compounds, characterized by the drastic lattice contraction at TC, is presumably responsible for this great entropy change.
- NaZn13-type intermetallic compounds /
- large negative thermal expansion /
- magnetic entropy change

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