Anelastic relaxation process of polaronic origin in La{2-x}Sr{x}CuO{4}: interaction between the charge stripes and pinning centers

TL;DR

This study investigates an anelastic relaxation process in La{2-x}Sr{x}CuO{4} related to charge stripe dynamics and polaronic mechanisms, revealing how doping influences stripe order and relaxation characteristics.

Contribution

It provides new insights into the doping-dependent behavior of charge stripes and their interaction with pinning centers in La{2-x}Sr{x}CuO{4}, linking anelastic relaxation to stripe order transitions.

Findings

Relaxation peak disappears at x=0.2 doping.

Peak intensity correlates with polaronic charge stripe behavior.

Peak amplitude and energy barrier change near x=1/8 doping.

Abstract

The evolution of an anelastic relaxation process occurring around 80 K in La{2-x}Sr{x}CuO{4} at a measuring frequency of ~1 kHz has been followed from x = 0.0075 to the overdoped region, x = 0.2, 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 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.