NMR probe of pseudogap characteristics in Fe2+xV1-xAl

Article

关键词: ELECTRONIC-STRUCTURE;    FE2VAL;    ALLOYS;    CRYSTALLINE;    COMPOUND;    BEHAVIOR;    CO;   

DOI  :  10.1103/PhysRevB.61.9863

来源: SCIE

【 摘 要 】

We report the results of a V-51 nuclear magnetic resonance (NMR) study of Fe2+xV1-xAl, near the ordered composition with x = 0, at temperatures between 4 and 500 K. All compositions are found to be metallic or semimetallic, though electrical resistivity has indicated a metal-insulator transition at x = 0. The low-temperature NMR relaxation rates for stoichiometric (x = 0) and nonstoichiometric (x = 0.10 and - 0.05) compounds follow a Korringa law, associated with a finite density of carriers at the Fermi level. High-temperature relaxation rates for x less than or equal to 0 go over to a semiconductorlike activated form, providing information about the gap structure near the Fermi energy. The results are consistent with pseudogap features identified by recent band-structure calculations, although with smaller energy splittings. We analyze pseudogap changes vs composition, and compare the band-filling behavior to a recent coherent potential approximation calculation.

【 授权许可】

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