Anomalous magnetism in decagonal Al69.8Pd12.1Mn18.1

Article

关键词: ICOSAHEDRAL QUASI-CRYSTAL;    AL-MN ALLOYS;    THERMAL-CONDUCTIVITY;    TRANSITION METALS;    SINGLE-GRAIN;    MOMENTS;    NMR;    PD;    HO;    SYMMETRY;   

DOI  :  10.1103/PhysRevB.68.134204

来源: SCIE

【 摘 要 】

We report the results of measurements of Al-27 and Mn-55 NMR spectra, the related spin-lattice relaxation rates, and the dc magnetic susceptibility of the stable decagonal quasicrystal Al69.8Pd12.1Mn18.2. The temperature variation of the magnetic susceptibility chi(T) reveals that the Mn ions carry only an effective magnetic moment of approximately 2mu(B), and confirms a spin-glass-type freezing of the Mn moments at T-f=12 K. The NMR spectra reveal two partially resolved lines for the Al-27-nuclei, indicating that there are two different sets of environments for the Al-sites. The integrated intensity of the Mn line in the spectra suggests that about half of the Mn ions carry no magnetic moment. Below 50 K, and upon decreasing the temperature, the Al-27 NMR linewidth w and the spin-lattice relaxation rate T-1(-1) both grow with an increasingly negative slope, as it is often observed and interpreted as a critical slowing down of magnetic moments in systems approaching a spin-glass transition. Various features, such as a broad maximum in T-1(-1)(T) and a slope change in the w(chi) plot, both around 120 K, suggest a gradual reduction of the number of Mn moments with decreasing temperature below 120 K.

【 授权许可】

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