迪拉克半金属Ca_{0.6}Sr_{0.4}MnSb_{2}中的自旋波,通过衍射方法与中子进行研究
Xiao Hu1, Yan Wu2, Matthias D Frontzek2
1Brookhaven National Laboratory, Condensed Matter Physics and Materials Science Division, Upton, New York 11973, USA.
Physical review letters
|April 7, 2025
概括
离子替代不会调整迪拉克半金属中的磁性合. 相反,基化合物中的晶格对称性变化可能导致层间磁性合中观察到的标志变化.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学是一种材料科学.
- 固态化学 固态化学
背景情况:
- 具有反铁磁 (Mn) 层的迪拉克半金属具有非常有趣的调节性质.
- 在CaMnBi2和SrMnBi2之间层间磁性合的信号变化表明离子替代作为调机制.
- 在磁性补偿点附近探索新奇的行为至关重要.
研究的目的:
- 研究离子替代和Sb替代Bi对Ca0.6Sr0.4MnSb2.2中的磁性合的影响.
- 确定电离体大小或晶格对称性是否控制了磁合的观察到的信号变化.
- 开发一种有效的方法来研究小晶体中的自旋动力学.
主要方法:
- 利用广角区域探测器的中子衍射,从小 (≈0.28 g) 的Ca0.6Sr0.4MnSb2晶体中获得旋波信号.
- 应用了自旋波建模,结合了能量-动量保存,以分析光谱信息.
- 将结果与SrMnSb2进行比较,以了解离子替代和晶格结构的影响.
主要成果:
- 从小晶体获得高质量的自旋波信号,证明了用于自旋动力学研究的有效方法.
- 旋波建模揭示了Ca0.6Sr0.4MnSb2中的层间合,其数量类似于SrMnSb2.
- 这些发现表明,离子大小并不直接调整层间磁性合.
结论:
- 在基于Bi的化合物中,层间磁性合的标志变化很可能是由于格子对称度的变化,而不是离子大小.
- 离子替代不是调整这些迪拉克半金属中的磁性合的主要机制.
- 开发的中子衍射方法可以在有限的样本大小中进行有效的旋转动态的参数和组成研究.
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