The microstructural properties of (Ba0.5Sr0.5)TiO3(BSTO) thin films (300, 7
00, and 1400 nm thick) deposited on LaAlO3 (LAO) substrates were characteri
zed using high-resolution x-ray diffractometery. Film crystallinity was the
parameter that most directly influenced tunability, and we observed that a
) the crystalline quality was highest in the thinnest film and progressivel
y degraded with increasing film thickness; and b) strain at the film/substr
ate interface was completely relieved via dislocation formation. Paraelectr
ic films such as BSTO offer an attractive means of incorporating low-cost p
hase shifter circuitry into beam-steerable reflectarray antennas.