Low-temperature specific heat of USb and UTe

We have measured the low-temperature specific heat c_p of single-crystalline samples of USb and UTe between 0.1 and 12 K. From the experimental data we deduce values for the electronic specific-heat parameter γ of 0.2 mJ/mole K² and 10.3 mJ/mole K² for USb and UTe, respectively. c_p data below 1 K reveal the onset of nuclear specific heat with decreasing temperature. In our temperature range, this contribution is much stronger for USb than for UTe.