A Y-89 NMR study of Bi2Sr2Ca1-xYxCu2Oy (0.1 <= x <= 1.0)

High resolution Y-89 NMR measurements have been carried our to study the ef fect of Y substitution in Bi2Sr2Ca1-xYxCu2Oy. A single resonance line was o bserved for samples with x greater than or equal to 0.5, while an additiona l line was observed for x < 0.5, possibly arising from Y which occupies the Sr site. The resonance of the Y on the Ca site shifts diamagnetically upon increasing the carrier concentration and paramagnetically upon reducing th e temperature, in dose relation with the variation of T-c in the system. (C ) 1999 Elsevier Science B.V. All rights reserved.