The effect of high-pressure synthesis on flux pinning in MgB2-based superconductors

Tatiana Prikhna (1) , Wolfgang Gawalek (2) , Michael Eisterer (3) , Harald Weber (3) , Mykola Monastyrov (1) , Vladimir Sokolovsky (4) , Jacques Noudem (5) , Viktor Moshchil (1) , Myroslav Karpets (1) , Valeriy Kovylaev (1) , Alexandr Borimskiy (1) , Vasiliy Tkach (1) , Artem Kozyrev (1) , Roman Kuznietsov (1) , Jan Dellith (2) , Christa Shmidt (2) , Doris Litzkendorf (2) , Friedrich Karau (6) , Ulrich Dittrich (6) , Michael Tomsic (7)

1 NASU - National Academy of Sciences of Ukraine
2 Leibniz IPHT - Leibniz Institute of Photonic Technology
3 TU Wien - Vienna University of Technology = Technische Universität Wien
4 BGU - Ben-Gurion University of the Negev
5 CRISMAT - Laboratoire de cristallographie et sciences des matériaux
6 H.C. Starck
7 Hyper Tech Research, Inc

Increasing the pressure during manufacturing MgB2 enhances the volume pinning force and moves the position of the maximum to higher magnetic fields. A similar shift was observed when Ti or SiC was added and the maximum of the volume pinning force was found at higher fields in in situ synthesized materials than in ex situ sintered samples. We attribute the observed changes to Mg–B–O oxygen-enriched regions and grains of higher magnesium borides in the MgB2 matrix. High-temperature processed materials demonstrated mainly point or mixed pinning while grain boundary pinning dominated after low-temperature synthesis.

Mots clés: Magnesium diboride; Pinning force; Critical current density; Pinning centers; Higher magnesium borides

Domaines: Sciences de l'ingénieur [physics]; Sciences de l'environnement; Physique [physics]; Matériaux; Milieux fluides et réactifs

Tatiana Prikhna, Wolfgang Gawalek, Michael Eisterer, Harald Weber, Mykola Monastyrov, et al.. The effect of high-pressure synthesis on flux pinning in MgB2-based superconductors. Physica C: Superconductivity, 2012, 479, pp.111-114. ⟨10.1016/j.physc.2012.01.004⟩. ⟨hal-02150589⟩