title: The phase analysis of spark plasma sintered MgB2 after ball milling.
abstract: Mg and amorphous B powders below 10 and 3 micro meter were used as raw materials, and mixed by planetary-mill for 9 hours at argon atmosphere. MgB2 bulk was fabricated at the various temperatures by Spark Plasma Sintering. In the sintering process, mixed powders were sintered in graphite mold, at the pressure of 55 Mpa. The fabricated MgB2 samples were evaluated with XRD, EDS, FE-SEM, PPMS. MgB2, MgO and Fe phases were observed from XRD result. In the results, MgO and Fe were impurity which may affect superconducting properties of MgB2 samples, and it's distribution could be confirmed from EDS mapping result. In order to confirm the formation of MgB2 phase, DTA was used as heating rate of 10 degrees C/min at Ar atmosphere from room temperature to 1200 degrees C. In the PPMS result, the Tc (critical temperature) was about 21 K, and the density of spark plasma sintered samples increased to 1.87 g/cm3 by increasing sintering temperature.
authors.affiliation: School of Nano and Advanced Materials Engineering, I-Cube Center K-MEM R&D cluster, Gyeongsang National University, Jinju 660-701, Korea.
authors.forename: Deuk-Kyun
authors.initials: DK
authors.lastname: Kang
authors.forename: Dong-Woong
authors.initials: DW
authors.lastname: Kim
authors.forename: Cheol-Jin
authors.initials: CJ
authors.lastname: Kim
authors.forename: In-Shup
authors.initials: IS
authors.lastname: Ahn