AN EXPOSITION OF INHOMOGENEOUS MAGNETIC STATES IN TYPE-I AND TYPE-II SUPERCONDUCTORS BY SQUID MAGNETOMETRY

The inhomogeneity of the intermediate and the mixed states of type I and type II superconductors can manifest as contributions from multipole moments higher than dipole moment of the specimen to the "measured magnetization signal". By performing careful magnetization (M) measurements with a SQUID magnetometer on disc-shaped superconducting specimens of lead (type I) and niobium (type II), we show that contributions from higher multipole moments are clearly visible in that part of the magnetization hysteresis curve where it crosses the M = 0 axis.