Abstract
The magnetic excitation spectrum of a crystal containing 0.5% of nonmagnetic (Zn) impurities has been determined by inelastic neutron scattering. Whereas in the pure system a sharp resonance peak at is observed exclusively below the superconducting transition temperature , the magnetic response in the Zn-substituted system is broadened significantly and vanishes at a temperature much higher than . The energy-integrated spectral weight observed near increases with Zn substitution, and only about half of the spectral weight is removed at .
- Received 27 August 1998
DOI:https://doi.org/10.1103/PhysRevLett.82.1939
©1999 American Physical Society