Strain-induced changes of oxygen ordering inYBa2Cu3O6+δcuprates

Abstract

Local elastic strain may significantly alter oxygen ordering in superconducting cuprates due to the change in bond lengths and crystal symmetry, thus altering their superconducting properties. To explore this phenomenon, the Bragg-Willams and Bethe order-disorder theories were used in this study. We demonstrate that oxygen ordering may exist in locally strained regions at any finite temperature and that applied stresses change the overall order-disorder transition temperature. The states of order in oxygen-ordering domains near an edge dislocation and a twin tip in ${\text{YBa}}_{2}{\text{Cu}}_{3}{\text{O}}_{6+x}$ were calculated in both the low-temperature orthorhombic and high-temperature tetragonal. In the orthorhombic phase, both deviatoric and hydrostatic components of stress alter the degree of oxygen ordering at a given temperature and alter the superconducting transition temperature.