LOW-TEMPERATURE SPECIFIC-HEAT OF VSI2, NBSI2, AND TASI2

We present low temperature specific heat measurements of VSi2, NbSi2 and TaSi2. The three disilicides crystallize in the same hexagonal structure (C40, space group P6(2)22). The measured values of the electronic Density of States at the Fermi Energy, D(E(F)), are in good agreement with theoretical band structure calculations. The obtained Debye temperatures vary as M-1/2 (M is the molar mass of the compound), showing that the interatomic forces are similar in the three disilicides. NbSi2 and TaSi2 are found to be superconductors at 0.130 K and 0.353 K respectively. The variation of the transition temperatures is discussed