ChemInform Abstract: Growth of Epitaxial MgB2Thick Films with Columnar Structures by Using HPCVD

Epitaxial MgB2 thick films are grown on Al2O3 substrates at 600 °C by using the hybrid physical (HP)CVD technique. In order to obtain a high magnesium vapor pressure around the substrates, we use a special susceptor having a susceptor cap and achieve a very high growth rate of 0.17 μm min–1. Hexagonal-shaped columnar structures are observed by cross-sectional and planar-view transmission electron microscope (TEM) images. For the 1.7 μm thick film, the Tc is observed to be 40.5 K with a Jc of 1.5 × 106 A cm–2 at 30 K. The vortex pinning mechanism by intercolumnar boundaries will be discussed.