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Autori: C R Rotundu, K Ingersent, and B Andraka
Editorial: Physical Review B, 75, p.104504, 2007.
Resistivity measurements were performed on Pr1-xLaxOs4Sb12 single crystals at temperatures down to
20 mK and in fields up to 18 T. The results for dilute-Pr samples x=0.3 and 0.67 are consistent with model
calculations performed assuming a singlet crystalline-electric-field CEF ground state. The residual resistivity
of these crystals features a smeared step centered around 9 T, the predicted crossing field for the lowest CEF
levels. The CEF contribution to the magnetoresistance has a weaker-than-calculated dependence on the field
direction, suggesting that interactions omitted from the CEF model lead to avoided crossing in the effective
levels of the Pr3+ ion. The dome-shaped magnetoresistance observed for x=0 and 0.05 cannot be reproduced by
the CEF model, and likely results from fluctuations in the field-induced antiferroquadrupolar phase.
Cuvinte cheie: heavy-fermion