Control of strain relaxation in tensile and compressive oxide thin films

Tensile and compressive solid-solution thin films based on LaAlO3 and CaZrO3 compositions were grown on perovskite oxide substrates using pulsed laser deposition to study growth mode transitions and strain relaxation. A buried layer of SrRuO3 between the thin film and the SrTiO3 substrate was also introduced to provide an auxiliary embedded strain gauge, which helps identify the critical conditions for the onset of catastrophic strain relaxation events – cracking and dislocation cascades. The results are compared with theoretical predictions to provide guidelines on some general deposition conditions that may be used to obtain smooth, crystalline and defect-free thin films of interest to perovskite-based heterostructures.