Low Field ac Susceptibility and High Harmonic Study in Chevrel-Phase and High-Tc Polycrystalline Superconductors

Abstract

The ac susceptibility and high harmonic response of polycrystalline SnMo6S8 and YBa2Cu3Oy superconductors are measured in the presence of small ac excitation field and dc magnetic field applied on it. Critical state models are used to explain the nonlinear magnetic response in polycrystalline superconductors. For Chevrel‐phase superconductors, a field independent Bean’s critical state model and for High‐Tc superconductor the Anderson‐Kim model are observed to work reasonably well.