MICROSTRUCTURE PROCESS RELATIONS IN SOL-GEL-PREPARED KNBO3 THIN-FILMSON (100) MGO

Epitaxial (110) orthorhombic KNbO3 thin films were prepared using alko xide solutions. Single-phase films were produced with stoichiometric s ols while slight variations in stoichiometry (52/48 Nb/K or 48/52 Nb/K ) created residual second phases. Nucleation and growth of KNbO3 as a function of process conditions were monitored by observing the KNbO3 r osettes produced from niobium-rich solutions. Methanolic solutions pro duced films with the highest rosette density and the highest amount of KNbO3. Hydrolysis of the sol aided the crystallization of the KNbO3 p hase but also promoted the formation of second phases. Hydrolysis at 0 -degrees-C reduced second-phase formation.