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arXiv · 0806.0207

Similar glassy features in the NMR response of pure and disordered La1.88Sr0.12CuO4

V. F. Mitrovic·M. -H. Julien·C. de Vaulx·M. Horvatic·C. Berthier·T. Suzuki·K. Yamada
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Abstract

High Tc superconductivity in La2-xSrxCuO4 coexists with (striped and glassy) magnetic order. Here, we report NMR measurements of the 139La spin-lattice relaxation, which displays a stretched-exponential time dependence, in both pure and disordered x=0.12 single crystals. An analysis in terms of a distribution of relaxation rates T1^-1 indicates that i) the spin-freezing temperature is spatially inhomogeneous with an onset at Tg(onset)=20 K for the pristine samples, and ii) the width of the T1^-1 distribution in the vicinity of Tg(onset) is insensitive to an ~1% level of atomic disorder in CuO2 planes. This suggests that the stretched-exponential 139La relaxation, considered as a manifestation of the systems glassiness, may not arise from quenched disorder.

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V. F. Mitrovic, M. -H. Julien, C. de Vaulx, M. Horvatic, C. Berthier, T. Suzuki, K. Yamada. 2008-06-02. Similar glassy features in the NMR response of pure and disordered La1.88Sr0.12CuO4. https://doi.org/10.1103/physrevb.78.014504

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