TY  - THES
TY  - BOOK
T1  - The effects of silicone tetraboride addition on the phase formation of magnesium diboride
A1  - Chow, Wai Hon.
LA  - English
UL  - http://discoverylib.upm.edu.my/discovery/Record/278251
AB  - It has been proven that Magnesium Diboride will be more effective in term of current carrying if added with dopants.  This is the main concern of this thesis, which aims to investigate the effects and phase formation of Silicone Tetraboride addition on Magnesium Diboride.  Previously, much study has been clone on Silicon Carbide or Titanium Carbide doped with Magnesium Diboride.  It will be more interesting to know the effects of non-carbide Silicone Tetraboride (SiB4) as dopant addition on Magnesium Diboride.  In this work, SiB4 was added to MgB2 according to weight percentage of 0.5%, 1%, 2% and 5%.  The samples are being sintered in 650°C and 800°C respectively as in this range of temperature, better superconducting properties can be obtained. The evolution of microstructure, phase formation and the effect of adding dopants on the resistivity of Magnesium Diboride are investigated by using X-ray diffraction, Scanning Electron Microscope and Van der Pauw method.  In XRD analysis, hkl values for MgB2 peaks have been determined and the existence of second phases such as unreact magnesium, Mg2Si, MgB4 and excess SiB4 has been revealed.  The microstructure of MgB2 and other impurity grains has been viewed by using SEM.  It is found that addition of SiB4 has effectively enhanced the resistivity of the samples.  In term of sintering temperature, higher temperature shows significant low resistivity compared to the samples sintered at low temperature.
CN  - FS 2008 136
ER  -