Anomalous Magnetism of the High-Tc Superconductors with Rare-Earth and/or Transition Element Ions–Static Susceptibility with Resistivity–

Abstract

A series of the high-Tc superconductors Y–Ba–Cu–O system substituted Y– by rare earth ions Eu–, Gd–, Ho– or/and –Cu– by transition element ions –Mn–, –Ni– have been studied at 4.2∼120K from a stand-point of magnetism by using a microwave SQUID at 9 GHz. Anomalous coexistence of the magnetic phase with perfect diamagnetism in Ho–Ba–Cu–Oxide has been observed, whereas substitution of –Cu– by transition element ions yields delicate effects on superconductivity.