Thermodynamics analysis on BaF2 intermediate phase in solution-derived YBCO superconducting film deposition

TL;DR

This study analyzes the thermodynamic stability of BaF2 during YBCO superconducting film fabrication, revealing formation priorities and potential compound formation at various temperatures through Gibbs free energy calculations.

Contribution

It provides a detailed thermodynamic analysis of BaF2 in YBCO film deposition, using two methods to predict phase stability and formation tendencies.

Findings

BaF2 is thermodynamically stable at higher temperatures.

BaCO3 formation is possible at 700 K.

BaF2 formation priority increases with temperature.

Abstract

In the YBa2Cu3O7-{\delta} (YBCO) high temperature superconducting thin film fabrication via the chemical solution deposition method, BaF2 is an important intermediate phase during heat treatment. In this paper, BaF2 thermodynamics stability was analyzed through calculating the standard Gibbs free energy change ({\Delta}GT) of the reactions related to other intermediate phases within the temperature range of 700-1000 K. Two thermodynamics methods, the Gibbs free energy function method and standard formation molar Gibbs free energy method, were utilized to obtain the {\Delta}GT values. The formation priority of BaF2 relative to other intermediate phases were verified at higher temperatures, while the possibility of BaCO3 formation was found at 700 K.