Recent progress in cryochemical synthesis of oxide materials

Abstract

Recently conventional cryochemical processes have been complemented by cryoextraction, cryoprecipitation, cryoimpregnation and freeze casting techniques. Considerably more attention is being paid to colloidal solution processing and the application of sol-gel procedures like ion exchange treatment and hydrolysis of organometallic compounds. New preparation methods for nanopowders of various oxides and metals have been developed while further treatment of cryochemical powders using powder engineering techniques allows the powder grain size to vary from 0.2 to 5-6 µm. Cryochemical methods are also suitable for preparation of various porous media, like porous silica or cryogels with surface areas close to those of aerogels, and for the synthesis of HTSC powders for different applications. Fundamental and applied aspects of cryochemical processing are discussed.