Probing the Yb$^{3+}$ spin relaxation in Y$_{0.98}$Yb$_{0.02}$Ba$_{2}$Cu$_{3}$O$_{x}$ by Electron Paramagnetic Resonance

A. Maisuradze; A. Shengelaya; B. I. Kochelaev; E. Pomjakushina; K. Conder; H. Keller; K. A. Müller

doi:10.1103/PhysRevB.79.054519

paper

Probing the Yb $^{3 +}$ spin relaxation in Y $_{0.98}$ Yb $_{0.02}$ Ba $_{2}$ Cu $_{3}$ O $_{x}$ by Electron Paramagnetic Resonance

arXiv:0901.3525 · doi:10.1103/PhysRevB.79.054519

Abstract

The relaxation of Yb $^{3 +}$ in YBa $_{2}$ Cu $_{3}$ O $_{x}$ ( $6 < x < 7$ ) was studied using Electron Paramagnetic Resonance (EPR). It was found that both electronic and phononic processes contribute to the Yb $^{3 +}$ relaxation. The phononic part of the relaxation has an exponential temperature dependence, which can be explained by a Raman process via the coupling to high-energy ( $\sim$ 500 K) optical phonons or an Orbach-like process via the excited vibronic levels of the Cu $^{2 +}$ ions (localized Slonczewski-modes). In a sample with a maximum oxygen doping $x$ =6.98, the electronic part of the relaxation follows a Korringa law in the normal state and strongly decreases below $T_{c}$ . Comparison of the samples with and without Zn doping proved that the superconducting gap opening is responsible for the sharp decrease of Yb $^{3 +}$ relaxation in YBa $_{2}$ Cu $_{3}$ O $_{6.98}$ . It was shown that the electronic part of the Yb $^{3 +}$ relaxation in the superconducting state follows the same temperature dependence as $^{63}$ Cu and $^{17}$ O nuclear relaxations despite the huge difference between the corresponding electronic and nuclear relaxation rates.

arXiv comment8 pages, 6 figures

Probing the Yb $^{3 +}$ spin relaxation in Y $_{0.98}$ Yb $_{0.02}$ Ba $_{2}$ Cu $_{3}$ O $_{x}$ by Electron Paramagnetic Resonance

Abstract

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Probing the Yb3+ spin relaxation in Y0.98​Yb0.02​Ba2​Cu3​Ox​ by Electron Paramagnetic Resonance

Abstract

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Cited by in corpus (2)

Probing the Yb $^{3 +}$ spin relaxation in Y $_{0.98}$ Yb $_{0.02}$ Ba $_{2}$ Cu $_{3}$ O $_{x}$ by Electron Paramagnetic Resonance