Magnetic Susceptibility of Fe-Doped YBa2Cu3O7-δ

Abstract

Magnetic properties of YBa₂(Cu_1-x Fe _x )₃O_7-δ with 0≦x≦0.085 were investigated by dc- and ac-magnetic susceptibility in a temperature range from 4.2 to 300 K. The susceptibility in the normal state follows the Curie-Weiss law χ=C/(T-\varTheta)+χ₀ with constant paramagnetism χ₀. The effective magnetic moments estimated from the Curie constant are 3.4∼4.0 µ_B/Fe, which are consistent with the magnetic moment obtained in the Mössbauer experiments. From the ac susceptibility in the superconducting state, a decrease of volume fraction of superconductivity was observed with increasing Fe-concentration.