MgB2 fabrication by diffusion-controlled three layered (B-Mg-B) technique

ALTIN S., AKSAN M. A., YAKINCI M. C.

JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, cilt.72, sa.9, ss.1070-1076, 2011 (SCI-Expanded, Scopus)

Özet

MgB2 was successfully fabricated through diffusion-controlled three-layered (B-Mg-B) technique under high pressure. Due to melting temperature of Mg, the material was pre-heat treated at 600 degrees C between 1 and 48 h. Optimum pre-heat treatment condition was found to be 600 degrees C for 48 h. Then, the compacted material was grinded and pelletized under pressure of 2 ton. The pellets were heat treated at 600-900 degrees C for 1-48 h. Optimum heat treatment condition was determined to be 800 degrees C for 1 h for formation of almost pure MgB2. Diffusion coefficient was determined with Fick's law and EDX data. Diffusion coefficient value for B in Mg matrix and Mg in B matrix was determined to be 1.66 x 10(-7) and 3.14 x 10(-8) cm(2)/sn, respectively. Best T-c value (39.4 K) was obtained for material heat treated at 800 degrees C for 1 h. A symmetric hysteresis was obtained for the best MgB2 material and magnetization decreased with increase in the temperature and the applied magnetic field. (C) 2011 Elsevier Ltd. All rights reserved.