Paraelectric (Ba/sub 0.6/Sr/sub 0.4/)TiO/sub 3/ thick films by direct-write

MicroPen/spl trade/ direct-write technique has been used to fabricate polycrystalline paraelectric BST 60/40 11-140 /spl mu/m thick films on alumina substrates. The dielectric properties of the thick films were studied as a function of film thickness, microstructure, and the state of residual stresses. Sin/sup 2//spl Psi/ X-ray analyses indicated a compressive state of stress in the films which decreased from /spl sim/40 MPa at 36 /spl mu/m to /spl sim/15 MPa at 140 /spl mu/m. The cubic/spl rarr/tetragonal transition temperature was found to be -10/spl deg/C. No thickness dependence of the transition temperature was observed. Field induced polarization curves also indicate no apparent nonlinear behavior up to 4 kV/mm.