Growth of high-quality large-area MgB2 thin films by reactive evaporation

We report a new in situ reactive deposition thin film growth technique for the production of MgB2 thin films which offers several advantages over all existing methods and is the first deposition method to enable the production of high-quality MgB2 films for real-world applications. We have used this growth method, which incorporates a rotating pocket heater, to deposit MgB2 films on a variety of substrates, including single-crystalline, polycrystalline, metallic, and semiconductor materials up to 4 inch in diameter. This technique allows growth of double-sided, large-area films in the intermediate temperature range of 400-600 degrees C. These films are clean, well-connected, and consistently display T-c values of 38 - 39 K with low resistivity and residual resistivity values. They are also robust and uncommonly stable upon exposure to atmosphere and water.