Synthesis and Properties of c-axis Oriented Epitaxial MgB2 Thin Films

Abstract

We report the growth and properties of epitaxial MgB2 thin films on (0001) Al2O3 substrates. The MgB2 thin films were prepared by depositing boron films via RF magnetron sputtering, followed by a post-deposition anneal at 850C in magnesium vapor. X-ray diffraction and cross-sectional TEM reveal that the epitaxial MgB2 films are oriented with their c-axis normal to the (0001) Al2O3 substrate and a 30 degree rotation in the ab-plane with respect to the substrate. The critical temperature was found to be 35 K and the anisotropy ratio, Hc2(parallel to the film) / Hc2(pendicular to the film), about 3 at 25K. The critical current densities at 4.2 K and 20 K (at 1 T perpendicular magnetic field) are 5x10E6 A/cm2 and 1x10E6 A/cm2, respectively. The controlled growth of epitaxial MgB2 thin films opens a new avenue in both understanding superconductivity in MgB2 and technological applications.

10 pages, 6 figures

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Cited by in corpus (12)

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• High-field superconductivity in alloyed MgB2 thin films
• Template engineering of Co-doped BaFe2As2 single-crystal thin films
• Effect of two bands on critical fields in MgB2 thin films with various resistivity values
• Thermally-activated current transport in MgB_2 films
• Growth methods of c-axis oriented MgB2 thin films by pulsed laser deposition
• Pulsed Laser Deposition of epitaxial titanium diboride thin films
• A sol-gel method for growing superconducting MgB2 films
• Modification of intergrain connectivity, upper critical field anisotropy, and critical current density in ion irradiated MgB2 films
• Off-axis MgB2 films using an in situ annealing pulsed laser deposition method
• Nanogranular MgB2 thin films on SiC buffered Si substrates prepared by in-situ method
• Epitaxial MgB2 thin films on ZrB2 buffer layers: structural characterization by synchrotron radiation