Magnetization and peak effect of several single crystals ofV3Si

Magnetization is measured on several A15 ${\mathrm{V}}_3$Si single crystals. The magnetization curve of the purest sample, which is a high-κ superconductor in the pure limit, is fairly reversible, accompanied by an upward curvature near $H_{c2}$ probably caused by the Pauli paramagnetic effect. Those of the other samples show the peak effect near $H_{c2}$, and a scaling law between the pinning force density $F_P$ and the magnetic field holds. The magnetic induction B changes nonlinearly across the sample, and the sign of $d^2$B/${\mathrm{dr}}^2$ changes at the field where $F_P$ attains a maximum. The strain also shows the peak effect near $H_{c2}$, corresponding closely to that of the pinning force.