Application of a small oscillating magnetic field to reveal the peak effect in the resistivity of Nb3Sn

By the application of a small oscillating magnetic field parallel to the main magnetic field and perpendicular to the transport current, we were able to unveil the peak effect in the resistivity data of Nb$_3$Sn near the upper critical field $H_{c2}$. We investigated the dependence of this effect on the frequency and the amplitude of the oscillating magnetic field and show that the used technique can be more sensitive to detect the peak effect in a certain range of temperatures and magnetic fields than conventional magnetization measurements.