Preparation, cracteractise a nd compare thin film of nano particle Lanthanum yttrate with tem perature v ariations

The s ol-gel synth esis of metal oxides off ers new pos sibilities in the field of solid state io nic's. The chemical design of mol ecular precu rsors allows a better control of the polymeri zation proces s so that Taylor-made materials could be o btained. N ew hybrid organic-inorganic comp ounds exhibit high ionic conductivities and could be used as electrolyte s. Oxide gels are actually particle h ydrates. W ater adsorpt ion and dissociation at the oxide-water interfa ce are respon sible for th eir properties as ion exchangers or fast proton conductors. C olloidal par ticles are v ery small s o that the large solid-l iquid interface provide s improved electrochemical prope rties which can be used for making reversible cathodes or electro chromic devices. The sol-gel deposition of thin coatings of large area coul d open the possibility to make multilayer micro-ionic devices [۱]. Som e aspects of the simulta neous optimization of m aterial properties of proton conductors which are relevant f or their use in electroche mical cells such as fuel cells, electr ochemical re actors and sensors (high proton con ductivity, chemical, electrochemica l and morph ological sta bility) are discussed [۲ , ۳]. Condu ctivity measurements s how that doped-LaYO۳ is a p-type semiconductor at high oxygen partial pressures, but beco mes a pure o xide-ion conductor at l ow oxygen p artial press ures [۴, ۵].

کلیدواژه ها:

Lant hanum yttrate ، Fuel cell ، Solid electrolyte ، Sol-gel