B-11 and Al-27 NMR spin-lattice relaxation and Knight shift of Mg1-xAlxB2: Evidence for an anisotropic Fermi surface

Article

关键词: TRANSITION;    MGB2;    SUPERCONDUCTIVITY;   

DOI  :  10.1103/PhysRevB.66.140514

来源: SCIE

【 摘 要 】

We report a detailed study of the B-11 and Al-27 NMR spin-lattice relaxation rates (1/T-1) and the Al-27 Knight shift (K) in Mg1-xAlxB2, 0less than or equal toxless than or equal to1. The evolution of (1/T1T) and K with x is in excellent agreement with the prediction of ab initio calculations of a highly anisotropic Fermi surface, consisting mainly of hole-type two-dimensional (2D) cylindrical sheets from bonding 2p(x,y) boron orbitals. The density of states at the Fermi level also decreases sharply on Al doping and the 2D sheets collapse at xapproximate to0.55, where the superconducting phase disappears.

【 授权许可】

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