Recent progress in cryochemical synthesis of oxide materials

Recently conventional cryochemical processes have been complemented by cryo extraction, cryoprecipitation, cryoimpregnation and freeze casting techniqu es. Considerably more attention is being paid to colloidal solution process ing and the application of sol-gel procedures like ion exchange treatment a nd hydrolysis of organometallic compounds. New preparation methods for nano powders of various oxides and metals have been developed while further trea tment of cryochemical powders using powder engineering techniques allows th e powder grain size to vary from 0.2 to 5-6 mu m. Cryochemical methods are also suitable for preparation of various porous media, like porous silica o r cryogels with surface areas close to those of aerogels, and for the synth esis of HTSC powders for different applications. Fundamental and applied as pects of cryochemical processing are discussed.