C-AXIS ORIENTED FERROELECTRIC SRBI2(TAXNB2-X)O-9 THIN-FILMS

c-Axis oriented SrBi2(TaxNb2-x)O-9 (SBTN) ferroelectric thin films (0 < x < 2) have been deposited, for the first time, using pulsed laser ablation. Films were stoichiometries close to the target composition were deposited successfully on MgO(100)/Pt(100) substrates. X-ray diffraction analysis of the films showed a predominant (00l) orientation with small amounts of (115) and (200) orientations. The c-axis orientation was introduced primarily by choosing(100) Pt as the substrate material which has a lattice spacing close to the lattice parameter a (basal plane) in the pseudo-tetragonal unit cell of the layered structure ferroelectric material. The orientation effect is also attributed to the high energy of the depositing species, which is characteristic of the laser ablation process. The films show very good ferroelectric properties at room temperature and no fatigue up to 10(9) cycles. For example, SBTN films with a composition close to x = 0.8 show a remnant polarization value of 11 mu C cm, a coercive field of 45 kV cm(-1) and a resistivity of 4 x 10(13) Omega cm. Comparison of these values with those obtained from films with no preferred (00l) orientation indicate a significant drop in the coercive field by 20 kV(-2) cm(-1) and an increase in resistivity by an order of magnitude in the c-axis oriented films.