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arXiv 1509.02544cond-mat.mtrl-sci
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铁磁性Fe5PB2和Fe5SiB2的磁性和结构性质及Co和Mn取代的影响

Magnetic and structural properties of ferromagnetic Fe5PB2 and Fe5SiB2 and effects of Co and Mn substitutions

Michael A. McGuire, David S. Parker

摘要:

报道了Fe 5 PB 2、Fe 4CoPB 2、Fe 4 MnPB 2、Fe 5SiB 2、Fe 4CoSiB 2和Fe 4 MnSiB 2的晶体结构和磁性。它们都采用四元Cr 5 B3结构类型,并且在室温下是铁磁性的,易磁化轴沿c轴。在Fe 5SiB 2中的自旋重取向被观察为在170 K附近的磁化中的异常,并且被Co或Mn替代Fe抑制。发现硅化物通常比磷化物具有更大的磁矩,但是数据表明硅化物中的磁各向异性更小。钴取代使居里温度降低100 K以上,有序磁矩降低16- 20%,而锰取代的影响要小得多。这表明Mn磁矩与Fe铁磁性对齐,并且Co在这些结构中不具有有序磁矩。在Fe 5 PB 2和Fe 5SiB 2中观察到各向异性的热膨胀,沿着Fe 5SiB 2的c轴观察到负的热膨胀。本文报道了Fe_5SiB_2和Fe_4 MnSiB_2磁性的第一性原理计算。计算结果包括磁矩和各向异性,与实验结果符合较好.

英文摘要:

Crystallographic and magnetic properties of Fe5PB2, Fe4CoPB2, Fe4MnPB2, Fe5SiB2, Fe4CoSiB2, and Fe4MnSiB2 are reported. All adopt the tetragonal Cr5B3 structure-type and are ferromagnetic at room temperature with easy axis of magnetization along the c-axis. The spin reorientation in Fe5SiB2 is observed as an anomaly in the magnetization near 170 K, and is suppressed by substitution of Co or Mn for Fe. The silicides are found to generally have larger magnetic moments than the phosphides, but the data suggests smaller magnetic anisotropy in the silicides. Cobalt substitution reduces the Curie temperatures by more than 100 K and ordered magnetic moments by 16-20%, while manganese substitution has a much smaller effect. This suggests Mn moments align ferromagnetically with the Fe and that Co does not have an ordered moment in these structures. Anisotropic thermal expansion is observed in Fe5PB2 and Fe5SiB2, with negative thermal expansion seen along the c-axis of Fe5SiB2. First principles calculations of the magnetic properties of Fe5SiB2 and Fe4MnSiB2 are reported. The results, including the magnetic moment and anisotropy, and are in good agreement with experiment.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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