论文标题
自旋动力学和熵稳定的氧化物抗铁磁铁中几乎连续的磁相变
Spin dynamics and a nearly continuous magnetic phase transition in an entropy-stabilized oxide antiferromagnet
论文作者
论文摘要
抗铁磁熵稳定的氧化物（mg $ _ {0.2} $ co $ _ {0.2} $ ni $ _ {0.2} $ _ {0.2} $ cu $ _ {0.2} $ _ {0.2} $ zn $ _ {0.2} $（mogo-go-eso）的磁性顺序和旋转动态中子散射。我们发现，抗铁磁序在样品体积中逐渐发展，因为它冷却在140 K以下，在100 K左右完全排序。自旋动力学在过渡附近显示出严重的减慢，并且磁性参数在有序状态下不断增长。这些结果表明，抗铁磁过渡是连续的，但以高斯的订购温度分布进行。同样，由非弹性中子散射确定的特定热量的磁性贡献也显示出一个较大的特征，该特征左右在120 K附近。高分辨率的非弹性中子散射进一步揭示了在低温下最初散布的频谱，从而发现加热后的准循环贡献增加直至订购温度。
The magnetic order and the spin dynamics in the antiferromagnetic entropy-stabilized oxide (Mg$_{0.2}$Co$_{0.2}$Ni$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$)O (MgO-ESO) have been studied using muon spin relaxation ($μ$SR) and inelastic neutron scattering. We find that antiferromagnetic order develops gradually in the sample volume as it is cooled below 140 K, becoming fully ordered around 100 K. The spin dynamics show a critical slowing down in the vicinity of the transition, and the magnetic order parameter grows continuously in the ordered state. These results indicate that the antiferromagnetic transition is continuous but proceeds with a Gaussian distribution of ordering temperatures. The magnetic contribution to the specific heat determined from inelastic neutron scattering likewise shows a broad feature centered around 120 K. High-resolution inelastic neutron scattering further reveals an initially gapped spectrum at low temperature which sees an increase in a quasielastic contribution upon heating until the ordering temperature.
