MgB2 thin films fabrication and structuring

Chiara Portesi 2Eugenio Monticone 2Valeria Dellarocca 1Renato S. Gonnelli 1

1. Dipartimento di Fisica, Politecnico di Torino, Italy, corso Duca degli Abruzzi, 24, Torino 10129, Italy
2. Istituto Elettrotecnico Nazionale "Galileo Ferraris", Italy (IEN), Strada delle Cacce, 91, Torino 10135, Italy

Abstract

Since the discovery of its superconducting properties, magnesium diboride has generated a great interest because of its simple structure, relatively high critical temperature and pronounced two-gap nature. These properties make this superconductor good for many potential applications.
In this work, we present the results obtained in the fabrication, characterization and structuring of MgB2 thin film grown by so-called in situ method. This technique consisted in two steps: the first one was the co-deposition of B and Mg by means of e-gun and resistive heater respectively. During the deposition .the substrate was held at temperature of 280C.The second step was the annealing of the as-grown films in the deposition chamber at 500C in inert atmosphere.
Using this method, we obtained MgB2 thin films with rather good electrical properties and smooth and homogeneous surfaces. The analysis of the morphological and structural properties has been performed by means of AFM and XRD respectively. The critical temperature was about 32 -35 degrees and we always observed very sharp transitions; the roughness of the samples was ranging between 10 and 20 nm (if evaluated on 5 mm2 areas), and it was strongly dependent on the films thickness. The films were polycrystalline, with a columnar growth of the grains and in the best samples we observed a partial orientation along the c-axis.
The samples were structured using standard photolithographic process followed by chemical wet etching or by dry etching. For the chemical etching, we experimented different acid solutions and the best results have been obtained using HCl solution (0.05%),in which the sample was dipped for a few second.. By ion milling, we realized well defined 5 microns wide strips with very sharp edges.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/1983 must be provided.

 

Related papers
  1. The superconducting gaps of C-substituted and Al-substituted MgB2 single crystals by point-contact spectroscopy
  2. MgB2 THICK FILMS OBTAINED BY ELECTROPHORESIS TECHNIQUE: SYNTHESIS, STRUCTURAL AND SUPERCONDUCTIVE CHARACTERIZATION
  3. Nano SiC doped MgB2 bulk superconductor with Tc over 42 K by high gas pressure annealing
  4. Comparison between radiation hardness of Bi2Sr2Ca2Cu3Ox tapes and MgB2 tapes and films

Presentation: poster at E-MRS Fall Meeting 2004, Symposium E, by Chiara Portesi
See On-line Journal of E-MRS Fall Meeting 2004

Submitted: 2004-04-30 17:33
Revised:   2009-06-08 12:55
Google
 
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine