Novel sol-gel fabrication of BaMgF4 thin films using single-source alkaline-earth β-diketonate fluorinated compounds

In the last decades, BaMgF₄ based materials represent key systems for several optical applications. The present study explores the optimization of sol-gel conditions for producing pure BaMgF₄ thin films on Si (100) substrates by varying precursor ratios and annealing temperatures. Three approaches were examined using different molar ratios of [Ba(hfa)₂•tetraglyme] to [Mg(hfa)₂•2H₂O]•2diglyme. The synthetic method combines sol-gel and spin-coating techniques, utilizing the fluorinated β-diketonate [Ba(hfa)₂•tetraglyme] and [Mg(hfa)₂•2H₂O]•2diglyme as single-source precursors. X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), and scanning electron microscopy (SEM) analysis were employed to characterize film composition, crystalline phases, and morphology. The study underscores the critical role of precursor hydrolysis efficiency, with the [Ba(hfa)₂•tetraglyme] precursor demonstrating superior performance in producing good-quality BaMgF₄ films. These findings provide insights into precise control over precursor chemistry and processing conditions, essential for optimizing film quality and advancing potential applications in optoelectronic devices.