Study of Transforming and NontransformingV3Si up to 29 kbar

Well-characterized transforming (T) and nontransforming (NT) ${\mathrm{V}}_3$Si single-crystal samples have been investigated under hydrostatic pressures up to 29 kbar. Above the critical pressure $P_c$, the superconducting transition temperature $T_c$ of the T sample was found to increase continuously with pressure, with only a reduction in $\frac{\partial T_c}{\partial P}$. The value of $\frac{\partial T_c}{\partial P}$ for the T sample above $P_c$ is similar as to that for the NT sample. A pressure-induced phase transition in the NT sample at 28.6 kbar was observed. The results are discussed and compared with some of the predictions of various models on $A15$ high-$T_c$ superconductors.