Statistical comparative analysis of microwave and conventionally annealed sol–gel derived metal oxide thin films

Abstract The influence of conventional furnace annealing and microwave annealing on sol–gel-derived TiO₂ and NiTiO₃ thin films was investigated through a statistically supported comparison. Thin films were prepared by spin coating and subsequently heat-treated using the two annealing methods under controlled conditions. Structural, morphological, optical, dielectric, and electrical properties were examined using XRD, SEM, AFM, UV–visible spectroscopy, C–V, and I–V measurements. Reproducibility of the results was assessed using statistical analysis based on mean and standard deviation, along with significance testing. Microwave annealing produced noticeable and statistically significant changes in crystallite size, optical band gap, and leakage current density when compared with conventional annealing. However, visible transmittance and dielectric permittivity showed only minor differences between the two methods. The results also revealed material-dependent behaviour, particularly in surface roughness and crystallite growth. Overall, the study shows that microwave annealing can achieve similar or improved film properties in a much shorter processing time, making it a practical alternative to conventional furnace annealing for sol–gel-derived metal oxide thin films.