Title :
Crystal growth and critical current densities of polycrystalline MgB2 superconductor
Author :
Maeda, Minoru ; Mizuno, Kenichiro ; Takashi, Akao ; Uchiyama, Daisuke ; Kawakami, Takateru ; Kobayashi, Hisayasu ; Yasohama, Kazuhiko ; Kubota, Yoji
Author_Institution :
Coll. of Sci. & Technol., Nihon-Univ. Inst. of Phys., Tokyo, Japan
fDate :
6/1/2005 12:00:00 AM
Abstract :
We have investigated crystal growth and critical current densities of MgB2 which was synthesized using stoichiometry or excess Mg and two kinds of B grain size. Excess Mg plays a role not only to promote crystal growth but also to make crystal grains fine. During crystal growth, the critical current densities decrease, although the density remains constant, approximately. Irrespective of the starting B powder, JCM is the highest in the sample with the smallest crystal grains and highest density of MgB2. The effects of excess Mg creates the possibility to control crystal size of MgB2 by adjusting the quantity of Mg.
Keywords :
critical current density (superconductivity); crystal growth; grain boundaries; grain growth; grain size; magnesium compounds; stoichiometry; type II superconductors; B grain size; MgB2; critical current density; crystal grains; crystal growth; excess Mg; magnesium diboride; polycrystalline MgB2 superconductor; stoichiometry; Critical current density; Electron tubes; Grain size; High temperature superconductors; Multifilamentary superconductors; Physics; Powders; Superconducting thin films; Superconducting transition temperature; Transistors; Critical current densities; crystal grains; crystal growth; excess Mg; magnesium diboride;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2005.848857
