Andrius Stanulis

Sol–gel (combustion) synthesis and characterization of different alkaline earth metal (Ca, Sr, Ba) stannates

In this study, monophasic strontium and barium stannate (SrSnO3, Sr2SnO4, BaSnO3, Ba2SnO4) powders were synthesized by means of environmentally friendly aqueous sol–gel technique under neutral conditions. However, it was established that the successful sol–gel synthesis of appropriate calcium stannates (CaSnO3 and Ca2SnO4) can be performed only at acidic sol–gel processing conditions. Moreover, the influence of nature of alkaline earth metal source on the phase purity of different metal stannates was evaluated. The thermal behaviour of Ca–Sn–O, Sr–Sn–O and Ba–Sn–O precursor gels was investigated by TG-DSC measurements. The phase purity, crystallization peculiarities and microstructural evolution of the sol–gel derived alkaline earth metal stannate powders were studied by XRD and SEM measurements.

SnO2 thin films from an aqueous citrato peroxo Sn(IV) precursor

In this work, tin(II) oxalate was studied as a novel chloride-free starting material for the preparation of a stable Sn-containing precursor solution. This precursor was applied for the chemical solution deposition (CSD) of transparent conducting coatings of SnO2 on Si/SiO2 substrates. An influence of synthesis parameters, such as pH, complexing agent to metal ion ratio on the stability of the citrato peroxo Sn(IV) precursor has been investigated in this study. Insights into the precursor chemistry and its thermal decomposition based on TG-DSC analysis are also presented. The obtained SnO2 films were characterized by high temperature X-ray diffraction (HT-XRD) and scanning electron microscopy (SEM) to evaluate phase purity and film thickness, respectively.