Superconducting and Microstructural Properties of Two Types of MgB2 Films Prepared by Pulsed Laser Deposition

Authors

Y. Zhao, University of WollongongFollow
M. Ionescu, University of WollongongFollow
M. Roussel, University of WollongongFollow
A. V. Pan, University of WollongongFollow
J. Horvat, University of WollongongFollow
S. X. Dou, University of WollongongFollow

RIS ID

13660

Publication Details

This article was originally published as: Zhao, Y, Ionescu, M, Roussel, M et al, Superconducting and Microstructural Properties of Two Types of MgB2 Films Prepared by Pulsed Laser Deposition, IEEE Transactions on Applied Superconductivity, June 2005, 15(2), 3261-3264. Copyright IEEE 2005.

Abstract

Significant differences in superconducting and microstructural properties between two types of MgB₂ films prepared by pulsed laser deposition were determined. A very high H_c2-T slope of 1.1 T/K was achieved in the in situ film. The J_c-H curves of the in situ film also show a much weaker field dependence than that of the ex situ film. The magneto-optical (MO) images show that at 4 K the flux penetrates the in situ MgB₂ film through random paths, while for the ex situ film, the flux penetration pattern is mostly repeatable, indicating a defect-controlled flux penetration. Microstructural study (transmission electron microscopy and atomic force microscopy) revealed a relatively big grain size in the ex situ film. The correlation between the superconducting properties, microstructure and preparation conditions is discussed with regard to the two types of films.