Superconductivity News Forum (SNF)
Full Text, PDFHigh Magnetic Field Generated by Bulk MgB2 Prepared by Spark Plasma Sintering
Kévin Berger1, Michael Rudolf Koblischka3, Bruno Douine1, Jacques Noudem4, Pierre Bernstein4, Thomas Hauet2, and Jean Lévêque1
1University of Lorraine, GREEN, Research Group in Electrical engineering and Electronics of Nancy - EA 4366, Faculté des Sciences et Technologies, BP 70239, 54506 Vandoeuvre-lès-Nancy Cedex, France
2Institut Jean Lamour, Faculté des Sciences et Technologies, BP 70239, 54506 Vandoeuvre-lès-Nancy Cedex, France
3Institute of Experimental Physics, Saarland University, Campus C63, 66123, Saarbrücken, Germany
4CRISMAT, CNRS/ENSICAEN, 6 Boulevard du Maréchal Juin, 14050 CAEN Cedex 4, France
E-mail: [email protected]
Abstract — From the applications point of view, the advantage of low density given by MgB2 material must be taken into consideration and, the generation of strong magnetic flux densities using MgB2 should be investigated. In this contribution, we have studied the magnetic properties of samples processed by a fast Spark Plasma Sintering machine that is able to produce dense and high quality MgB2 samples. Experiments were carried out both on small pieces of the samples and on large-sized samples performing trapped field measurements in a Field-Cooling process. For temperatures between 10 K to 30 K, the results show a strong dependence of the magnetic behavior of the large-sized samples to the applied magnetic field sweep rate, while nothing particular appeared on the small samples. As the magnetic flux density produced by MgB2 bulks is directly linked to the potential of the applications, we report the field produced at the surface of one single MgB2 sample of 30 mm diameter and the field produced inside a stack of two MgB2 samples of 20 mm in diameter. A generation of magnetic flux density up to 4.8 T @ 10 K and 3.92 T @ 20 K inside the stack of the two MgB2 samples was observed. According to these values, thanks to their very low density and to their ease of manufacturing, MgB2 bulks are promising materials for the applications of superconductors.
Keywords (Index Terms) — Bulk MgB2, field-cooling process, flux jumps, strong magnetic field, trapped magnetic field.
IEEE/CSC & ESAS SUPERCONDUCTIVITY NEWS FORUM (global edition), January 2016.
Submitted September 18, 2015; Selected November 9, 2015. Reference No. ST484; Category 5.
EUCAS 2015 preprint 1A-M-O2.9. Submitted to IEEE Trans. Appl. Supercond. for possible publication.
Submitted September 18, 2015; Selected November 9, 2015. Reference No. ST484; Category 5.
EUCAS 2015 preprint 1A-M-O2.9. Submitted to IEEE Trans. Appl. Supercond. for possible publication.