Order-disorder transition and magnetic quantum oscillations in the vortex state of strong type-II superconductors

We present results of μSR, dHvA, and SQUID magnetization measurements on borocarbide superconductors, which show a remarkable correlation between an order-disorder transition of the vortex lattice, observed in the μSR measurements, and enhanced additional damping of dHvA oscillations in the peak-effect region. It is, therefore, concluded that an important mechanism of additional damping of dHvA oscillations in the superconducting state should be associated with enhanced scattering of quasi particles by the pair potential in disordered vortex lattices.