The evolution of an anelastic relaxation process occurring around 80 K in La22xSrxCuO4 at a measuring frequency of ;1 kHz has been followed from x50.0075 to the overdoped region x50.2, where it disappears. The dependence of the peak intensity on doping is consistent with a polaronic mechanism, identified with the disordered charge stripes overcoming pinning centers. A marked decrease of the peak amplitude and of the effective energy barrier for relaxation occurs at x.0.045, the same doping range where a change of the stripe order from parallel to diagonal with respect to the Cu-O bonds has been observed by neutron diffraction. Both the energy barrier and peak amplitude also exhibit a rise near x=1/8.
Anelastic relaxation process of polaronic origin in La2-xSrxCuO4: interaction between the charge stripes and pinning centers
FERRETTI, MAURIZIO
2003-01-01
Abstract
The evolution of an anelastic relaxation process occurring around 80 K in La22xSrxCuO4 at a measuring frequency of ;1 kHz has been followed from x50.0075 to the overdoped region x50.2, where it disappears. The dependence of the peak intensity on doping is consistent with a polaronic mechanism, identified with the disordered charge stripes overcoming pinning centers. A marked decrease of the peak amplitude and of the effective energy barrier for relaxation occurs at x.0.045, the same doping range where a change of the stripe order from parallel to diagonal with respect to the Cu-O bonds has been observed by neutron diffraction. Both the energy barrier and peak amplitude also exhibit a rise near x=1/8.
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