S. Kramer et al., Y-89-NMR experiments on the phase diagram and isotope effect of the Neel temperature in (YBa2Cu3O6+x)-O-16,18, PHYS ST S-B, 215(1), 1999, pp. 601-606
We report Y-89-NMR measurements in antiferromagnetic (YBa2Cu3O6+x)-O-16,18
powder samples at different doping levels. By a careful analysis of the tem
perature dependence of the spectral linewidth we were able to determine the
antiferromagnetic (AF) order parameter and the Neel temperature T-N of the
different samples. The resulting phase diagram was compared with neutron s
cattering results and theoretical calculations. Part of the samples were O-
18 enriched which provided experimental access to a possible isotope effect
of T-N in YBa2Cu3O6-x.