Bulk superconducting MgB2: pinning by grain boundaries or point defects?

Alex Wiederhold (1) , Michael Rudolf Koblischka (1) , Muralidhar Miryala (2) , Kazuo Inoue (2) , Thomas Hauet (3) , Bruno Douine (4) , Kévin Berger (4) , Masato Murakami (2) , Uwe Hartmann (1)

1 Institute of Experimental Physics
2 Superconducting Materials Laboratory
3 IJL - Institut Jean Lamour
4 GREEN - Groupe de Recherche en Electrotechnique et Electronique de Nancy

A series of disk-shaped, bulk MgB2 superconductors (sample diameter up to 4 cm) wasprepared in order to improve the performance for superconducting supermagnets [1-5]. Several samples were fabricated using a solid state reaction in pure Ar atmosphere from 750 to 950 °C in order to determine the optimum processing parameters to obtain the highestcritical current density as well as large trapped field values. The magnetic characterization measurements were performed using SQUID magnetometry (Quantum Design MPMS) and the magneto-resistance and I/V-characteristics were recorded using an Oxford Instruments 8 T Teslatron system.

Mots clés: supermagnets; MgB2; flux pinning forces; trapped fields

Domaines: Supraconductivité [cond-mat.supr-con]; Science des matériaux [cond-mat.mtrl-sci]; Electromagnétisme; Energie électrique

Alex Wiederhold, Michael Rudolf Koblischka, Muralidhar Miryala, Kazuo Inoue, Thomas Hauet, et al.. Bulk superconducting MgB2: pinning by grain boundaries or point defects?. NanoMaterials 2014 (MSnows 2014 and TransNano Forum), Sep 2014, Nancy, France. p. 112, id. P24, 2 p. ⟨hal-01060255v2⟩