Simplifying strong electronic correlations in uranium: Localized uranium heavy-fermion UM2Zn20 (M = Co, Rh) compounds

E. D. BAUERL. VILDOSOLA, A. M. LOBOS, A. A. ALIGIA, S. BOVEV, D. GARCÍA,J. L. SARRAO; C. WANG; V. R. FANELLI; J. M. LAWRENCE; E. A. GOREMYCHKIN; N. R. DE SOUZA; F. RONNING; J. D. THOMPSON; A. SILHANEK; V. VILDOSOLA; A. M. LOBOS; A. A. ALIGIA; S. BOBEV; J. L. SARRAO

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Año: 2008 vol. 78 p. 115120 - 115124

0163-1829

The physical properties including magnetic susceptibility, magnetization, specific heat, and dynamic susceptibility (E) are reported for single crystals of the cubic UM2Zn20  (M=Co,Rh) materials. Maxima in the thermodynamic data at Tmax~10  K for both compounds and a broad peak in (E) at 5 K in UCo2Zn20 of width =5  meV indicate a heavy-fermion state characterized by a Kondo temperature TK~20–30  K arising from weak hybridization of f- and conduction-electron states. Anderson impurity model fits to the data in the Kondo limit including crystalline electric-field effects corroborate an ionic-like uranium electronic configuration in UM2Zn20.