Hybrid physical-chemical vapor deposition (HPCVD) process was used for the deposition of MgB2 thin film. HPCVD process combined the thermal decomposition of diborane (B2H6) gas and the evaporation of Mg metal to provide sufficient Mg overpressure to maintain MgB2 phase stability at elevated temperature. The HPCVD-grown thin films was shown to be epitaxially oriented on SiC and sapphire single-crystal substrates with root-mean-square (RMS) roughness. A high superconductor fraction in the wire or tape cross-section and a thick superconductor coating was required to have a high engineering critical current density over the cross-sectional area on the entire wire. Experimental results showed that the thick MgB2 films were dense and polycrystalline with a preferred orientation. High current density values were obtained for undoped samples with thicknesses up to 10 μm and showed little degradation compared to results for thin films.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering