Ultralow temperature resonant X-ray diffraction study of the mechanism of multipole ordering in f-electron systems.

多极(四极、八极等…)的自由度在稀土和榄系元素中，化合物作为解决这一现象的关键引起了人们的注意，这一现象无法从过去的理论中得到理解。共振X射线衍射法(RXD)也就是这种研究方法是唯一可以直接检测多极有序化的实验技术。然而，由于几乎所有化合物中的多极子都在3K以下，国内的RXD实验是不可能的。本研究项目利用3He低温恒温器和入射X射线的偏振控制克服了这一问题，并使RXD实验能够在外加磁场的情况下进行。该实验环境在国内尚属首次实现。现在，我们对典型化合物的多极有序进行了深入的研究。

The degree of freedom of a multipole ( quadrupole and octupole etc…) in rare-earth and actinide compounds have attracted attention as a key that solves the mystery of the phenomenon that cannot be understood from a past theory. The resonance X-ray diffraction (RXD) method that is this studying method is the only experimental technique that can do the direct detection of the multipole ordering. However the RXD experiments domestically was impossible because the multipole in almost compounds order bellow 3 K. This research project overcomes this problem using 3He cryostat and the control of the polarization of incident X-ray, and, in addition, enables the RXD experiment applied the external magnetic field. This experiment environment was achieved for the first time domestically. Now we conduct in-depth research of multipole ordering on typical compounds.