Debye temperature in YBa2Cu3Ox as measured from the electron spin–lattice relaxation of doped Yb3+ ions

Abstract

The electron spin±lattice relaxation (SLR) times T 1 of Yb 3 ions were measured from the temperature dependence of electron spin resonance line width in Y 0X99 Yb 0X01 Ba 2 Cu 3 O x with dierent oxygen contents. Raman relaxation processes dominate the electron SLR. Derived from the temperature dependence of the SLR rate, the Debye temperature (H D ) increases with the critical temperature T c and oxygen content x. This relationship between T c and H D can be well understood in terms of the modi®ed Bardeen±Cooper±Schriefer theory of phonon mechanism for a strong electron± phonon coupling. Ó

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

“…) and, as we have shown for Yb 3+ and Er 3+ probes in YBaCuO compounds [6,7,8], caused by the 4f-electron-phonon interaction only. To determine the dominating spin-lattice relaxation process we use the next approach.…”

Probing theYb3+spin relaxation inY0.98Yb0.02Maisuradze1, Shengelaya2, Kochelaev3 et al. 2009Phys. Rev. BSelf Cite9150View full textAdd to dashboardCite

“…12 There have been a few EPR studies of the RE ions with non-zero orbital moment (Er and Yb) doped in cuprates. 13,14,15,16,17,18,19,20 Again, the situation with EPR is similarly contradictory as in INS studies. Some groups observed both electronic (Korringa) and phononic (Orbach) contributions to EPR relaxation.…”

“…13,16,17 While others conclude that the Korringa contribution is negligible and the interaction with lattice vibrations only is sufficient to explain the temperature dependence of the EPR linewidth in cuprates. 18,19,20 In this work we report a detailed EPR study of the Yb 3+ relaxation in YBa 2 Cu 3 O x samples with oxygen content x covering the whole doping range (6 < x < 7). By measuring the temperature dependence of the Yb 3+ EPR linewidth in a broad temperature range, it was found that both phononic and electronic mechanisms contribute to the relaxation.…”

Phonon Spectrum in Hydroxyapatite: Calculations and EPR Study at Low Temperatures

“…The influence of lattice vibrations on the relaxation rate is conventionally described in terms of Debye model [6] taking into account only acoustic phonons. It allows to fit the experimental EPR results adequately even for the high-temperature superconducting cuprates [20,21]. This simple approximation implies a parabolic phonon spectrum confined by the Debye frequency ω D (or corresponding Debye temperature D ) which is the one of the important parameters in solid-state physics.…”