Non-Fermi-liquid behavior and spin fluctuations in doped UAl2

Article

关键词: F-ELECTRON MATERIALS;    HEAVY FERMIONS;    SYSTEMS;    MAGNETISM;    ALLOY;    UPT3;   

DOI  :  10.1103/PhysRevB.55.947

来源: SCIE

【 摘 要 】

Using the canonical spin-fluctuation system UAl2 as a starting point, via negative chemical pressure (doping with Y) we have expanded d(U-U) in a system known to be near the Hill limit of f-electron localization, and characterized the samples via resistivity, magnetic susceptibility, and specific-heat measurements. All system parameters, including magnetic susceptibility, specific heat gamma(=C/T lim(T-->0)), and spin-fluctuation temperature, behave monotonically. For U1-xYxAl2, 0.30 less than or equal to x less than or equal to 0.70, spin-glass behavior is found with T-f similar or equal to 5.1+/-0.5 K. This spin-glass behavior weakens (T-f sinks, smaller magnetic signature, no specific-heat anomaly) for x greater than or equal to 0.75 while, at the same time, the spin-fluctuation T(3)lnT term also gradually disappears from the specific heat. For x greater than or equal to 0.875, a non-Fermi-liquid (nFl) lnT term is found in the low temperature C/T. This new, perhaps equilibrium, ground state persists upon further dilution of the U ions with Y. Thus, we report on the evolution of nFl behavior in the neighborhood of a spin-glass ground state but, indeed, directly out of a yet weaker form of magnetism than heretofore reported, that of spin fluctuations.

【 授权许可】

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