Muon Spin Relaxation and Nonmagnetic Kondo State in PrInAg_2

Authors :: MacLaughlin, D. E.
Heffner, R. H.
Nieuwenhuys, G. J.
Canfield, P. C.
Amato, A.
Baines, C.
Schenck, A.
Luke, G. M.
Fudamoto, Y.
Uemura, Y. J.
Publication Year :: 1998
Publisher :: arXiv, 1998.
Abstract: Muon spin relaxation experiments have been carried out in the Kondo compound PrInAg_2. The zero-field muon relaxation rate is found to be independent of temperature between 0.1 and 10 K, which rules out a magnetic origin (spin freezing or a conventional Kondo effect) for the previously-observed specific heat anomaly at \sim0.5 K. The low-temperature muon relaxation is quantitatively consistent with nuclear magnetism including hyperfine enhancement of the ^{141}Pr nuclear moment. This is strong evidence against a Pr^{3+} electronic magnetic moment, and for the \Gamma_3 crystalline-electric-field-split ground state required for a nonmagnetic route to heavy-electron behavior. The data imply the existence of an exchange interaction between neighboring Pr^{3+} ions of the order of 0.2 K in temperature units, which should be taken into account in a complete theory of a nonmagnetic Kondo effect in PrInAg_2.<br />Comment: 9 pages, 2 eps figures, REVTeX