Numerical Simulation of Nanorod Growth in REBa2Cu3Oy Superconducting Thin Films

Abstract

Various nanostructures consisting of BaMO 3 (BMO) self-organize in REBa 2 Cu 3 Oy (REBCO) films prepared by vapor phase epitaxy. A numerical simulation of the BMO self-organization was developed using the three-dimensional Monte Carlo (3D-MC) method, and the effects of deposition parameters such as substrate temperature (T s ), deposition rate (v dep ), and BMO volume fraction (f BMO ) on BMO self-organization were investigated. We consider only the kinetic factors and ignore mismatch strain on the nanorods (NRs) morphology. 3D-MC simulations for various T s indicated that the number density of BMO NRs decreased with an increase in T s , and this tendency was similar to previous experimental results for BaHfO 3 -doped SmBCO films prepared by the pulsed laser deposition method. The effects of v dep and f BMO were also simulated to provide contour plots of the number density of NRs with respect to T s and f BMO at various v dep . Phase diagrams of nanostructures consisting of BMO with various v dep were also obtained. Although these results do not take into account degradation of the superconducting properties and crystalline defects induced by nonoptimized conditions, they are considered to be a useful guideline for control of the flux pinning landscape on REBCO-coated conductors.