Single-crystal films are at the foundation of a number of advanced technologies, such as for devices related to microelectronics, optoelectronics, spintronics, and superconducting electronics. In this study, high-temperature annealing was used to rehabilitate the MgO(001) surface to improve the crystallinity of highly epitaxial LaBaCo2O5+δ (LBCO) films, which have demonstrated potential for applications in fast gas sensors. In comparison with the LBCO film grown on the as-received substrate, solid evidence is presented to support that the rehabbed substrates facilitate deposition of single-crystal LBCO films by radio frequency magnetron sputtering at the optimized conditions. Thus, substrate annealing is demonstrated to be a practical and effective method for rehabbing the damaged surface of a substrate induced by manufacture and surface milling and is promising for a range of important applications based on the growth of single-crystal films.

Perovskite LaBaCo2O5+δ (LBCO) single-crystal films were deposited on (001) MgO substrates by a magnetron sputtering method and processed into Pirani sensors for investigation of pressure measurements. In comparison to the poly-crystal film deposited under the same condition, the single-crystal LBCO films exhibited rather a large temperature coefficient of resistance and a high sensitivity in response to pressure. The LBCO sensors with dimensions of 30 to 200 μm, which are different from resistor-on-dielectric membrane or micro-beam structures, demonstrated to be capable of making response to the pressures ranging from 5 × 10–2 to 105 Pa with a real dynamic range of 3 to 2 × 103 Pa.