论文标题
热力学洞察力对$ _ {4} $的复杂磁相图
Thermodynamic insights into the intricate magnetic phase diagram of EuAl$_{4}$
论文作者
论文摘要
四方金属间化合物Eual $ _ {4} $容纳各种低温阶段。除了低于140 K的电荷密度波外，在15.4 K以下还观察到四个有序的磁相。最近，基于$ C $轴磁场下的Hall效应测量值提出了一个天空量相。我们介绍了对$ c $轴磁场下的$ _ {4} $中的相变的详细研究。我们的扩张法，热容量，DC磁力测定法，AC磁化敏感性和谐振超声光谱测量结果揭示了先前未报道的三个磁相变。我们讨论了有关磁相特征的结果。我们的第一个关键结果是详细的$ h \ parallel [001] $磁相图映射我们观察到的七个阶段。其次，我们确定了一个新的高场相VII，直接与该区域相对应的是Skyrmions。我们的结果为将来的研究提供了指导，探索了$ _ {4} $中复杂的磁相互作用和旋转结构。
The tetragonal intermetallic compound EuAl$_{4}$ hosts an exciting variety of low temperature phases. In addition to a charge density wave below 140 K, four ordered magnetic phases are observed below 15.4 K. Recently, a skyrmion phase was proposed based on Hall effect measurements under a $c$-axis magnetic field. We present a detailed investigation of the phase transitions in EuAl$_{4}$ under $c$-axis magnetic field. Our dilatometry, heat capacity, DC magnetometry, AC magnetic susceptibility, and resonant ultrasound spectroscopy measurements reveal three magnetic phase transitions not previously reported. We discuss what our results reveal about the character of the magnetic phases. Our first key result is a detailed $H \parallel [001]$ magnetic phase diagram mapping the seven phases we observe. Second, we identify a new high-field phase, phase VII, which directly corresponds to the region were skyrmions have been suggested. Our results provide guidance for future studies exploring the complex magnetic interactions and spin structures in EuAl$_{4}$.
