No abstract

The specific heat as a function of temperature between 1.4 and 10 K for fields between 28 and 45 T reveals a small anomaly in the C/T data that is first visible at 32 T. The anomaly grows in size monotonically up to our highest field of measurement ͑45 T͒; the temperature of the maximum of the specific heat anomaly grows as well with increasing field at approximately 0.21 K/T, up to a value of T peak ϭ4.1 K at 45 T. Thermodynamic considerations indicate that the field-induced transition is first order. The data are compared to the weak metamagnetic transition in the magnetization observed around 42 T by Takeuchi et al.

Specific heat and magnetization results as a function of field on single-and poly-crystalline samples of Ce 1−x La x RhIn 5 show 1.) a specific heat γ of about 100 mJ/moleK 2 (in agreement with recent dHvA results of Alvers et al.); 2.) upturns at low temperatures in C/T and χ that fit a power law behavior (<=> Griffiths phase non-Fermi liquid behavior); 3.) a field induced anomaly in C/T as well as M vs H behavior in good agreement with the recent Griffiths phase theory of Castro Neto and Jones, where M˜H at low field, M˜H λ above a crossover field, C/T˜T −1+λ at low field, and C/T˜(H 2+λ/2 /T 3−λ/2 )*exp(µ ef f H/T) above the same crossover field as determined in the magnetization and where λ is independently determined from the temperature dependence of χ at low temperatures, χ˜T −1+λ and low fields.