Temperature dependence of the EPR linewidth of Yb3+ ions in Y0.99Yb0.01Ba2Cu3OX (6 ≤ X ≤ 7) compounds: Evidence for an anomaly near the superconducting transition

Abstract

Electron paramagnetic resonance experiments on doped Yb3+ ions in Y0.99Yb0.01Ba2Cu3OX (6 ≤ X ≤ 7) compounds with different oxygen contents have been made. We have observed a strong temperature dependence of the EPR linewidth in all the investigated samples caused by the Raman processes of spin-lattice relaxation. The spin-lattice relaxation rate anomaly revealed near TC in the superconducting species can be assigned to the phonon density spectrum changes. © 2005 IOP Publishing Ltd.