TaSi2, and NbSi2 are superconductors below 353 mK and 130 mK respectively. These compounds, like VSi2 which is not superconducting down to 100 mK, crystallise in the C40 structure. They differ by a slight variation of lattice parameters.
We have systematically investigated the superconducting properties of several samples of TaSi2 by magnetic and resistive measurements. A small difference on Tc is observed for the same crystal by the two techniques. Several explanations are presented for this result.
We also report a change of Tc under pressure in good agreement with those resulting of the volume variation for the two C40 superconductors previously studied.