The influence of structural defects on intragranular critical currents of bulk MgB[sub 2].

Conference · Tue Jan 01 00:00:00 EST 2002

OSTI ID:976295

Serquis, A ^[1]; Liao, Xiaozhou; Civale, L ^[2]; Zhu, Y T ^[3]; Coulter, J Y ^[4]; Peterson, D E ^[5]; Mueller, F M ^[6]

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1. Adriana
2. Leonardo
3. Yuntian Theodore
4. James Y.
5. Dean E.
6. Fred M.

Bulk MgB2 samples were prepared under different synthesis conditions and analyzed by scanning and transmission electron microscopy. The critical current densities were determined from the magnetization versus magnetic field curves of bulk and powder-dispersed-in-epoxy samples. Results show that through a slow cooling process, the oxygen dissolved in bulk MgB2 at high synthesis temperatures can segregate and form nanometer-sized coherent precipitates of Mg(B,O)2 in the MgB2 matrix. Magnetization measurements indicate that these precipitates act as effective flux pinning centers and therefore significantly improve the intra-grain critical current density and its field dependence.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE
• OSTI ID: 976295
• Report Number(s): LA-UR-02-5176; TRN: US201018%%1117
• Resource Relation: Conference: Submitted to: Proceedings Applied Superconductivity Conference, Houston
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRITICAL CURRENT
DEFECTS
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIZATION
OXYGEN
SUPERCONDUCTIVITY
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
MAGNESIUM BORIDES