Mj. Dalberth et al., IMPROVED LOW-FREQUENCY AND MICROWAVE DIELECTRIC RESPONSE IN STRONTIUM-TITANATE THIN-FILMS GROWN BY PULSED-LASER ABLATION, Applied physics letters, 72(4), 1998, pp. 507-509
We have grown epitaxial strontium titanate films on lanthanum aluminat
e substrates at a range of oxygen pressures and substrate temperatures
. The complex dielectric function was measured as a function of temper
ature and electric field bias using a microwave ring resonator and a f
lip-chip technique. The films having the highest dielectric constant w
ere grown with an oxygen pressure of 600 mTorr and showed large grains
in the plane of the film. The small-signal dielectric constant of the
se films could be changed by a factor of 4 by applying an electric fie
ld. The films with the highest dielectric constant showed increased lo
sses, but an improved figure of merit for application to tunable circu
its. (C) 1998 American Institute of Physics.