Gd3+EPR of High Temperature Superconductor GdBa2Cu3Ox

Abstract
EPR measurements of Gd 3+ were performed in the superconducting and non-superconducting GdBa 2 Cu 3 O x . There is no distinct difference between the EPR behaviors of the two samples. The results show that even in the superconducting sample, the Gd ions behave as paramagnetic local moments with a mutual exchange interaction of 0.1 K.