Oxygen Content Dependence of 63Cu(1) NQR and Proton NMR in Hydrogen-Doped Antiferromagnetic YBa2Cu3O6+xHy

Abstract

Abstract The oxygen content dependence of 63Cu NQR at the Cu(1) site and proton NMR have been measured in the antiferromagnetic phase of powdered samples of hydrogen-doped YBa2Cu3O6+xHy (0.07 <̲ x <̲ 0.17 and y ≈ 1) from 4.2 to 90 K. The spectrum of 1H NMR is a single line and the line width increases below 15 K due to magnetic interactions. The enhancements of T1 -1 and T2 -1 of 63Cu(l)NQR occur around 35 and 15 K, respectively. These enhancements increase with increasing oxygen concentration. The maximum values of T1 -1 and T2 -1 for the sample with x = 0.17 reach 200 sec-1 and more than 7 msec-1, respectively. The predominant source for the relaxation mechanism of 63Cu(l) NQR and the line broadening of 1H NMR are found to be the fluctuating magnetic field due to the staggered Cu2+ moments.