Spin correlation and slow dynamics in concentrated spin-glasses

缓慢动力学的问题也是自旋玻璃的核心问题，实验研究受到了宏观测量的限制，就像热残余磁性的时间演变一样。在先前的中子散射研究中，我们展示了磁性簇在不断的自旋玻璃过渡中发挥着重要的作用，并且通过非弹性中子散射研究观察到的自旋动力学的广泛变异可以归因于磁性簇的大小和数量的差异。根据这些研究，我们推测了缓慢动力学的机理可能是最直接地揭示了对磁性簇中磁性干扰散射的观测时间演变的结果。we made a time-resolved small-angle neutron scattering experiment on two kinds of concentrated spin glass alloys Fe D265（NiイイD21-xイD2MnイD2 xイD2）イD235イD2 and CuイD22イD2）MnイD21-xイD2TiイD2 xイD2）Al.The time variation of the magnetic diffuse scManagement int？after being quenched into the RSG phase was detected up to 20 hours。《观察》揭示了当前实验方法的敏感性的满足性，以及如何检测缓慢动态的条件。通过对计数统计数据的重复进行定量分析，通过重复相同的热周期，进行定量分析是行不通的。

Although the problem of slow dynamics is a central issue of spin-glass, experimental studies have been limited to macroscopic measurements, such as the time evolution of thermo-remnant magnetization. In previous neutron scattering studies we showed that magnetic clusters play an important role for the reentrant spin-glass transition, and that a wide variety of spin dynamics observed by inelastic neutron scattering studies can be attributed to differences in the size and number of the magnetic clusters. Based on these studies, we speculate that the mechanism of slow dynamics might most directly be probed by an observation of the time evolution of the magnetic diffuse scattering arising from magnetic clusters.In this work, we made a time-resolved small-angle neutron scattering experiment on two kinds of concentrated spin glass alloys FeィイD265ィエD2(NiィイD21-xィエD2MnィイD2xィエD2)ィイD235ィエD2 and CuィイD22ィエD2)MnィイD21-xィエD2TiィイD2xィエD2)Al.The time variation of the magnetic diffuse scattering intensity after being quenched into the RSG phase was detected up to 20 hours. The observation showed that the sensitivity of the present experimental method satisfies the condition to detect the slow dynamics. A quantitative analysis together with an improvement of the counting statistics by repetition of same heat cycles is under way.