Superconducting Properties And Crystallinity Of As-Grown Mgb2 Thin Films Synthesized Using An In-Plane-Lattice Near-Matched Epitaxial Buffer Layer

As-grown MgB2 thin films were synthesized at a low temperature of 270 degrees C on an in-plane-lattice-near-matched TiZr buffer layer grown on Al2O3-C substrate and Al2O3 substrate without buffer. The critical temperature (T-c), critical current density (J(c)) and crystallinity of MgB2 on TiZr buffered substrates were found to be high compared with those of MgB2 on Al2O3; the improved T-c was around 35 K and J(c) 6.6 x 10(5) A/cm(2) at 5 K under the magnetic field of I T perpendicular to the film surface. The epitaxial relationship of MgB2 thin film on buffer layer was MgB2 [01 - 10] parallel to TiZr[01 - 10] parallel to Al2O3 [11 - 20], but MgB2 thin film without buffer layer had no epitaxial relationship.