Microstructure of KTa sub x Nb sub 1 sub - sub x O sub 3 thin films on MgO(100) single crystals

Thin KTN films were prepared by deposition of sol-gel precursor solutions on MgO(100) single crystals. Crystal structure and microstructure of the films as a function of processing parameters, such as rate, duration, and temp. of postdeposition heat treatment, were studied. Slow heating of KTN films promoted pyrochlore formation while fast-firing of the films resulted in predominant formation of the perovskite phase. Films < or =1 mu m thick were obtained by multiple deposition of the sol-gel KTN. Dense films were achieved when each layer was densified at 750 degrees C for 2 h before the next layer was deposited.