Defect structure of ultrafine MgB{sub 2} nanoparticles
- Department of Chemistry, Koc University, Rumelifeneri Yolu, Sariyer, Istanbul (Turkey)
- Institut für Physikalische Chemie, Universität Freiburg, Albertstr. 21 79104 Freiburg (Germany)
- Freiburger Materialforschungzentrum (FMF) für Physikalische Chemie, Universität Freiburg, Stefan-Meier Str. 21 79104 Freiburg (Germany)
- Pavezyum Chemicals, Orhanlı Mah. Ulu Sokak, No. 3, 34956 Tuzla, Istanbul (Turkey)
Defect structure of MgB{sub 2} bulk and ultrafine particles, synthesized by solid state reaction route, have been investigated mainly by the aid of X-band electron paramagnetic resonance spectrometer. Two different amorphous Boron (B) precursors were used for the synthesis of MgB{sub 2}, namely, boron 95 (purity 95%–97%, <1.5 μm) and nanoboron (purity >98.5%, <250 nm), which revealed bulk and nanosized MgB{sub 2}, respectively. Scanning and transmission electron microscopy analysis demonstrate uniform and ultrafine morphology for nanosized MgB{sub 2} in comparison with bulk MgB{sub 2}. Powder X-ray diffraction data show that the concentration of the by-product MgO is significantly reduced when nanoboron is employed as precursor. It is observed that a significant average particle size reduction for MgB{sub 2} can be achieved only by using B particles of micron or nano size. The origin and the role of defect centers were also investigated and the results proved that at nanoscale MgB{sub 2} material contains Mg vacancies. Such vacancies influence the connectivity and the conductivity properties which are crucial for the superconductivity applications.
- OSTI ID:
- 22392025
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 20; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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