PREPARATION OF ION-EXCHANGEABLE THIN-FILMS OF LAYERED NIOBATE K4NB6O17

An ion-exchangeable thin film which has the layered structure of K4Nb6 O17 was prepared from a suspension of fine particles of K4Nb6O17. The superfine particles which were obtained by wet grinding were coated on to a substrate, and they were calcined between 873 and 1073 K. Crystal lization of the fine particles by calcination was observed by XRD, SEM , and AFM, and very flat crystals of similar to 500 nm with the b-axis perpendicular to the substrate surface were obtained by calcination a t 1027 K. The obtained thin film had a layered structure similar to th at of the original K4Nb6O17 powder. Furthermore, it had ion-exchange p roperties which enabled the exchange of interlayer cations from potass ium to others without destroying the layered structure.