Chemists and material scientists have often focused on the properties of previously reported compounds, but neglect numerous unreported but chemically plausible compounds that could have interesting properties. For example, the 18-valence electron ABX family of compounds features examples of topological insulators, thermoelectrics and piezoelectrics, but only 83 out of 483 of these possible compounds have been made. Using first-principles thermodynamics we examined the theoretical stability of the 400 unreported members and predict that 54 should be stable. Of those previously unreported 'missing' materials now predicted to be stable, 15 were grown in this study; X-ray studies agreed with the predicted crystal structure in all 15 cases. Among the predicted and characterized properties of the missing compounds are potential transparent conductors, thermoelectric materials and topological semimetals. This integrated process-prediction of functionality in unreported compounds followed by laboratory synthesis and characterization-could be a route to the systematic discovery of hitherto missing, realizable functional materials.

An environmentally friendly aqueous sol-gel process has been developed to fabricate thin films of indium tin oxide (ITO). A stable sol was prepared from indium nitrate and tin acetate precursors together with acetic acid and ethylene glycol. The sol transformed into an amorphous gel during heating, which decomposed and crystallized further to nano-crystalline ITO at $300 C. The nanocrystalline ITO powders prepared from the precursor gel were homogeneous and single phase with particle sizes around 15 nm. The aqueous sol was applied for spin coating of ITO films on glass substrates. The deposited thin films were homogeneous and continuous with no cracks or pin-holes and exhibited very good and reproducible optical transparency and electrical conductivity, with a specific resistance of 4.59 Â 10 À3 U cm, thereby demonstrating the potential of this Pechini related sol-gel process. Experiments to determine the robustness of the process with respect to the concentration of the precursors and substitution of the organic components with other alcohols or acids were also performed, and some important aspects of the chemistry of the sol-gel process are addressed.

The modified Pechini method has become one of the most popular synthesis methods for complex oxide materials due to its simplicity and versatility. The method can be applied to synthesize nano-crystalline powders, bulk materials as well as oxide thin films. Here, we present a comprehensive review of the method with focus on the chemistry through the three stages of the process; preparation of stable aqueous solution, poly-esterification to form a solid polymeric resin and finally decomposition/combustion of the resin to form an amorphous oxide followed by crystallization of the desired oxide phase. The review include several examples of important technical oxide materials where the method has been successfully been applied to prepare oxide powders, bulk or thin films.

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The modified Pechini method has become one of the most popular synthesis methods for complex oxide materials due to its simplicity and versatility. The method can be applied to synthesize nano-crystalline powders, bulk materials as well as oxide thin films. Here, we present a comprehensive review of the method with focus on the chemistry through the three stages of the process; preparation of stable aqueous solution, poly-esterification to form a solid polymeric resin and finally decomposition/combustion of the resin to form an amorphous oxide followed by crystallization of the desired oxide phase. The review include