NMR Investigation on the Electric Properties of Quasi-crystals

利用核磁共振技术研究了准晶的电子性质。我们的特别工作集中在了解准晶体的磁性，而不是它们的晶相。用单辊金属淬火技术制备了Al-Mn、Al-Mn-Si、Al-Mn-Si-Lu、Al-Li-Cu和Mg-Ga-Zn系的准晶，并对各合金进行了适当的热处理，得到了晶相。在这些合金中成功地观测到了Al、Mn、Li和Ga的核磁共振信号，测量了谱线轮廓和核弛豫时间随温度的变化关系。将这些结果与磁化率测量相结合，得出以下结论。1.对于含过渡金属的合金，只有Mn原子有磁矩。2.这些磁矩在准晶中得到了很强的增强，并且在某些准晶中观察到了自旋玻璃型磁序。3.从核弛豫研究来看，即使在非过渡金属合金中也观察到准晶磁性的增强。

The nuclear magnetic resonance (NMR) technique has been utilized to investigate the electronic properties of quasi-crystals. Our par-ticular efforts have been focused on understanding of the magnetic properties of quasi-crystals, in contrast to their crystal phases. The quasi-crystals of Al-Mn, Al-Mn-Si, Al-Mn-Si-Lu, Al-Li-Cu and Mg-Ga-Zn systems have been prepared by the single roller metalquenching technique and the crystal phases have been obtained by proper heat treatment of respective alloys. The Al, Mn, Li and Ga NMR signals have been successfully observed in these alloys and the temperature dependence of the line profile and the nuclear relaxation time have been measured. Combining these results with the susceptibility measurements, the following conclusions are emerged. 1. For the alloys with transition metals only the Mn atoms has magnetic moments. 2. These magnetic moments are strongly enhanced in the quasi-crystals and a spin glass type magnetic order has been observed some of the quasi-crystals. 3. From the nuclear relaxation studies, the enhancement of the magnetism in quasi-crystals has also been observed even in the non-transition metal alloys.