Simple Route to Grow High-Quality MgB₂Thin Films by Pyrolysis of Decaborane (B₁₀H₁₄) in Mg Vapor

We report the growth of MgB 2 films by thermally decomposing decaborane (B 10 H 14 ) in Mg vapor. B 10 H 14 , solid at ambient temperature and stable in air, is much more convenient to use as a boron source compared to highly explosive diborane (B 2 H 6 ) which is commonly used in the hybrid physical–chemical vapor deposition of MgB 2 films. MgB 2 films were grown on c -cut sapphire substrates held at 400–450 °C by supplying vaporized B 10 H 14 into a pocket heater with high Mg vapor pressure. The resultant films were phase-pure, c -axis oriented, and in-plane aligned, and had self-field critical current density of ∼3 × 10 7 A/cm 2 at 20 K.