Neutron spectroscopy of Nd1−v+yCavBa2−yCu3+zOx

Abstract The crystal field splitting in the high T c superconductor Nd 1- v+y Ca v Ba 2- y Cu 3+ z O x ( v =0, 0.5; y = 0, 0.25, 0.5; z =0, 0.5; 6.02⩽ x ⩽7.05) was observed by neutron spectroscopy. The charge transfer connected with doping could directly be measured by this local probe of the charge distribution around the rare earth site, and the determined values turned out to be comparable with that obtained by other methods.