Temperature dependence of the EPR linewidth of Yb3+ - ions in Y0.99Yb0.01Ba2Cu3OX compounds: Evidence for an anomaly near TC

TL;DR

This study investigates how the EPR linewidth of Yb3+ ions in YBaCuO compounds varies with temperature, revealing an anomaly near the critical temperature that suggests changes in phonon spectra related to superconductivity.

Contribution

It provides new insights into the temperature-dependent behavior of EPR linewidths in Yb3+ doped YBaCuO, highlighting an anomaly near TC linked to phonon spectrum changes.

Findings

EPR linewidth strongly depends on temperature due to spin-lattice relaxation.

An anomaly in relaxation rate appears near the superconducting transition temperature.

Phonon density spectrum changes are associated with the observed anomaly.

Abstract

Electron paramagnetic resonance experiments on doped Yb3+ ions in YBaCuO compounds with different oxygen contents have been made. We have observed the strong temperature dependence of the EPR linewidth in the all 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