Title :
Na Substitution Effects on MgB2 Synthesized With a Microwave-Assisted Technique
Author :
Agostino, Angelo ; Panetta, Marco ; Volpe, Paolo ; Truccato, Marco ; Cagliero, Stefano ; Gozzelino, Laura ; Gerbaldo, Roberto ; Ghigo, Gianluca ; Laviano, Francesco ; Lopardo, Giuseppina ; Minetti, Bruno
Author_Institution :
Univ. of Turin, Turin
fDate :
6/1/2007 12:00:00 AM
Abstract :
The effect of different Na doping levels on structural and electric transport properties MgB2 of bulk samples was investigated. The samples were synthesized by an assisted microwave method using the microwave radiation to heat the powder precursors (Mg and B, high purity) constrained in a stainless steel box. It was found that Na addition induces a small X-ray diffraction peak broadening. Moreover a slight decreasing of the critical temperature and an improvement of both the irreversibility field and the upper critical field are exhibited. The result is almost independent on the doping level. The pinning energy turns out to be higher for the doped samples even if its dependence on current and temperature is the same for doped and undoped samples. Doping effect, flux pinning, magnesium diboride, microwave synthesis, structural characterization.
Keywords :
X-ray diffraction; doping; flux pinning; magnesium compounds; sodium; superconducting critical field; superconducting materials; superconducting transition temperature; MgB2; Na doping; assisted microwave method; critical temperature; electric transport; irreversibility field; pinning energy; upper critical field; Doping; Electromagnetic heating; Flux pinning; Microwave ovens; Microwave theory and techniques; Powders; Steel; Superconducting materials; Temperature; X-ray diffraction; Doping effect; flux pinning; magnesium diboride; microwave synthesis; structural characterization;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
DOI :
10.1109/TASC.2007.900046
