Anomalies of the specific heat near the quantum critical point in Tm0.74Yb0.26B12

The behavior of the specific heat near the quantum critical point x similar to 0.3 in the Tm1 - x Yb (x) B-12 system has been studied. Detailed measurements have been performed on high-quality single-crystalline Tm0.74Yb0.26B12 samples within a wide temperature range of 1.9-300 K in a magnetic field up to 9 T. The temperature dependence of the magnetic contribution to the specific heat has a logarithmic divergence of the form C/T similar to lnT at T < 4 K, which can be attributed to the quantum critical behavior regime suppressed by the external magnetic field. The Schottky anomaly of the magnetic contribution to the specific heat in Tm0.74Yb0.26B12 has been analyzed.