Depression of order parameter and effect on grain boundary critical current density

✍ Scribed by K. Jagannadham; J. Narayan

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 989 KB
• Volume: 14
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(92)90120-x

✦ Synopsis

The depression of the order parameter at gram boundaries m lugh cnacal temperature superconduclang oxades is determined using two formulataons First, we use the Bardeen-Cooper-Schneffer formulation and assume formation of Cooper pairs by an attraclave mteraclaon potential The spalaal vanauon of the density of energy states at the Ferrm level near the boundary, estimated as a function of hydrostaUc stress field, is used to determine the depression of the order parameter Second, the proxtrmty-effect formulataon ~s used m the form of a boundary condmon on the order parameter at the interface The boundary condmons are solved taking into account the spatml vanalaon of the density of energy states The depression of the order parameter from the two formulalaons is used m conlunCtaon with atorme modeling to determine the cnt~cal current density assocmted with the gram boundaries The model correctly predicts dependence of the critical current density across gram boundanes on the mlsonentataon angle and temperature, m good agreement with experimental observalaons