Nuclear contribution to the specific heat of Yb(Rh0.93Co0.07)2Si2

Specific heat measurements of a Yb(Rh0.93Co0.07)(2)Si-2 high-quality single crystal in magnetic fields 0.5 <= mu H-0 <= 10 T and in the temperature range between 0.05 and 4 K are presented. To extract the electronic specific heat C-el from the raw data, and consequently the temperature dependence of the Sommerfeld coefficient gamma = C-el/T, the nuclear magnetic and electric contributions to the specific heat have been evaluated. The error between the experimental data below 1 K and the theoretical calculation varies between 0.9 and 8.7%, indicating that the coefficients used in our model are accurate and appropriate. The high-field ground state is confirmed to be a Fermi liquid. This analysis allows to determine the H-dependence of gamma for fields larger than 0.5 T and its change across the anomaly at mu H-0(0) approximate to 5.8T. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim