Physics / Fizik
Permanent URI for this collectionhttps://hdl.handle.net/11147/6
Browse
2 results
Search Results
Conference Object Citation - WoS: 3Citation - Scopus: 2Fabrication of Superconducting Mgb2 From Boron Oxide (b 2o3), and Its Microstructural and Electrical Characterization(National Institute of Optoelectronics, 2005) Yavaş, Mert; Okur, Salih; Eğilmez, Mehmet; Kalkancı, Mihriban; Özyüzer, LütfiThe discovery of superconducting MgB2 (39 K) draws attention to it as a new material for applications based on superconductivity. Many researchers successfully synthesized MgB2 using commercial boron and magnesium. In this study, elementary boron was obtained via an acid leaching process, after reacting B2O3, and Mg in an argon atmosphere at 800°C. Energy Dispersive X-ray Spectroscopy (EDX) results revealed that the powder obtained from the reaction was boron in 92% purity with magnesium as the major impurity. Superconducting MgB2 was produced from this boron and magnesium, in an argon atmosphere at 900°C, by a conventional solid-state reaction. Superconducting MgB2 powders were compressed in a dye to pellets by a hot pressing technique at 500°C and 1 GPa. The microstructural properties of the MgB2 were determined by X-ray Diffraction Spectroscopy, EDX, and Scanning Electron Microscopy techniques. The electrical properties of the fabricated MgB 2 were examined by resistivity measurements in a closed-cycle cryopump system, between 20 and 300 K. The critical temperature (Tc) of the MgB2 pellets was around 32 K.Conference Object Citation - WoS: 6Citation - Scopus: 5Electrical and Microstructural Properties of Superconducting Mgb 2/Mg Composites(Trans Tech Publications, 2004) Eğilmez, Mehmet; Günel, Aylin; Okur, Salih; Tanoğlu, Metin; Özyüzer, LütfiMgB2/Mg composites were prepared to improve mechanical properties of brittle superconducting MgB2. MgB2 and Mg powders were mixed at different weight ratios and uniaxially pressed in a cylindrical dye at 0.5 GPa and at various temperatures for two hours to prepare MgB2/Mg composites. X-ray diffraction, SEM and EDX were used for phase identification and microstructural characterization. In addition to the main MgB2 and Mg phases, the microstructural studies have indicated the presence of a minor amounts of second phases, namely MgO and B-rich compounds. The surface morphology, grain size and porosity ratio of the samples prepared under various temperatures were also investigated. The resistivity measurements were performed in the range of room temperature to 15 K. The effect of excess Mg and secondary phases on critical temperature of MgB2/Mg composites were studied.