在GdFe1-TSi,T=Cr,V,Ni中的磁热效应和磁性排序
A G Kuchin1, S P Platonov1, R D Mukhachev1
1M. N. Mikheev Institute of Metal Physics UB RAS, 620108 Ekaterinburg, Russia. kuchin@imp.uran.ru.
Physical chemistry chemical physics : PCCP
|May 30, 2023
概括
这项研究合成了基于GdFe的新型金属间化合物,揭示了用Cr,V或Ni进行兴奋剂显著改变了它们的磁性和基里温度. 一些化合物在室温附近表现出有希望的磁热效应.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 磁力学 磁力学 是一种
背景情况:
- 基于加多 (Gd) 和铁 (Fe) 的金属间化合物因其磁性特性而引起兴趣.
- 像GdFeSi这样的三级化合物通过替代提供可调节的特性.
- 了解组成,晶体结构和磁性行为之间的关系对于材料设计至关重要.
研究的目的:
- 为了合成和表征新的GdFe1-TSi (T = Cr,V,Ni) 金属间化合物.
- 研究T元素替代对库里温度 (TC) 和磁性排序的影响.
- 探索这些材料的磁热性质和潜在应用.
主要方法:
- 合成具有不同T含量 (Cr,V,Ni) 的GdFe1-TSi化合物.
- 实验确定库里温度 (TC) 和磁相过渡.
- 使用DFT+U方法进行第一原理计算,以确定电子结构,磁矩和磁顺序.
- 测量磁热效应 (MCE) 参数,包括异热磁变化 (-ΔSM) 和列宽.
主要成果:
- 合成的化合物结晶为四角形CeFeSi结构类型.
- TC随着Cr和V的替代而显著增加,而随着Ni的替代而减少.
- 在GdFe1-xNixSi在x = 0.3时观察到铁磁转变为抗铁磁转变,与格子参数变化相关.
- GdFe0.4Cr0.6Si和GdFe0.7V0.3Si在室温附近表现出显著的磁热效应 (TC ≈分别为255 K和250 K).
结论:
- 观察到的TC变化归因于状态密度的变化,受d-f交换相互作用的影响.
- 在GdFe1-xNixSi中的磁性状态 (铁磁/反铁磁) 与网格参数"c"有关.
- GdFe0.4Cr0.6Si和GdFe0.7V0.3Si化合物显示出磁性制冷应用的潜力,因为它们在室温附近的基里温度和显著的磁热效应.
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