Influence of high-angle grain boundaries on the charge order formation in the $\mathrm{YBa_2Cu_3O_{7-\delta}}$

TL;DR

This study investigates how high-angle grain boundaries in YBa2Cu3O7−δ influence charge order formation, highlighting defect interactions and the preferential formation near lattice defects and grain boundaries.

Contribution

It introduces a molecular dynamics analysis of defect interactions and demonstrates the role of high-angle grain boundaries in charge order formation in YBCO.

Findings

Charge order can form due to charged oxygen vacancies or di-vacancies.

High-angle grain boundaries are favorable sites for charge order formation.

A proportional relationship exists between grain boundary spacing and stripe embryo energy advantage.

Abstract

We are examining the possibility of the formation of charge order in the high-temperature superconductor $\mathrm{YBa_2Cu_3O_{7-\delta}}$ (YBCO) due to interaction between the charged oxygen vacancies or di-vacancies. The molecular dynamics method is used to analyze the displacement fields around these defects. The distribution of displacements around a single charged oxygen vacancy and di-vacancy, determination of binding energy of oxygen vacancy in di-vacancy demonstrate that there is, in principle, the possibility of the charge order formation in YBCO by charged oxygen vacancies or di-vacancies. It is shown that the charge order formation first of all should be formed near crystal lattice defects and that the high-angle grain boundaries (GBs) regions are preferable places for this formation. The adsorption capability of high-angle GBs with respect to the stripe embryo formation is determined. It is shown that there is a proportional dependence between the repetition distance along the high-angle GBs and an energy advantage of the stripe embryo formation in GBs.