Fine structure of a bulk MgB2 superconductor after deformation and heat treatment
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The structure of the MgB2 superconductor subjected to high-temperature restoration annealing after cold deformation under high pressure in a Toroid chamber or Bridgman anvils has been investigated by transmission electron microscopy. It has been shown that after postdeformation annealing at 950°C the average size of crystallites in the matrix phase increases 5–10 times compared to the deformed state, reaching ~50–150 nm, as well as the critical current density increases by a factor of three (up to 6.7 × 104 A/cm2, 30 K) compared to the initial state. It has been found that the MgO phase and the higher magnesium borides are present in the form of dispersed precipitates 10–70 nm in size.
Keywordsmagnesium diboride deformation annealing
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- 2.T. A. Prikhna, A. P. Shapovalov, A. V. Kozyrev, V. E. Moshchil, V. B. Sverdun, M. A. Belogolovskiy, G. E. Grechnev, V. G. Boutko, and A. A. Gusev, “Formation of nanostructure in magnesium diboride based materials with high superconducting characteristics,” Low Temp. Phys. 42, 380–394 (2016).CrossRefGoogle Scholar
- 3.Y. N. Akshentsev, M. V. Degtyarev, V. P. Pilyugin, T. P. Krinitsina, E. I. Kuznetsova, Y. V. Blinova, S. V. Sudareva, and E. P. Romanov, “Effect of deformation with Bridgman anvils on the structure, hardness, and critical current of a massive MgB2-based sample,” Phys. Met. Metallogr. 116, 475–481 (2015).CrossRefGoogle Scholar
- 5.I. F. Kislyak, M. A. Tikhonovsky, D. G. Malykhin, T. Yu. Rudycheva, V. G. Yarovoy, A. A. Blinkin, V. V. Derevyanko, S. Yu. Sayenko, G. A. Kholomeyev, A. G. Sivakov, A. S. Pokhila, and O. G. Turutanov, “Investigations of superconductivity in MgB2 bulk and Fe(steel)/MgB2 wires,” Vopr. At. Nauki Techn. Sverkhpr. Sverkhpr. Mater., No. 6, 107–110 (2009).Google Scholar
- 12.T. A. Prikhna, W. Gawalek, Ya. M. Savchuk, T. Habisreuther, M. Wendt, N. V. Sergienko, V. E. Moshchil, P. Nagorny, Ch. Schmidt, J. Dellith, U. Dittrich, D. Litzkendorf, V. S. Melnikov, and V. B. Sverdun, “The inclusions of Mg–B (MgB2) as potential pinning centers in high-pressure–high-temperature-synthesized or sintered magnesium diboride,” Supercond. Sci. Technol. 20, S257–S264 (2007).CrossRefGoogle Scholar
- 14.M. V. Degtyarev, V. P. Pilyugin, Y. N. Akshentsev, E. I. Kuznetsova, T. P. Krinitsina, Y. V. Blinova, S. V. Sudareva, and E. P. Romanov, “Influence of high-pressure deformation and annealing on the structure and properties of a bulk MgB2 superconductor,” Phys. Met. Metallogr. 117, 772–782 (2016).CrossRefGoogle Scholar
- 16.T. P. Krinitsina, E. I. Kuznetsova, Yu. V. Blinova, S. V. Sudareva, M. V. Degtyarev, E. P. Romanov, D. N. Rakov, and Yu. N. Belotelova, “Structure and stability of superconducting core of single-core MgB2/Cu,Nb tube composite with a high critical current,” Phys. Met. Metallogr. 115, 538–546 (2014).CrossRefGoogle Scholar