Microwave dielectric relaxation of the polycrystalline (Ba, Sr)TiO3 thin films -: art. no. 182904

The microwave dielectric properties of the (Ba,Sr)TiO3 thin films annealed at various oxygen pressures ranging from 5 to 500 mTorr were investigated over the frequency range 0.5-5 GHz using a circular-patch capacitor geometry. The dielectric constant (epsilon) followed Curie-von Schweidler relaxation in the microwave-frequency range; and the degree of relaxation corresponded qualitatively with the measured dielectric loss (tan delta). As the oxygen pressure varied, the dielectric loss had a maximum value of similar to 0.03 at 100 mTorr, and its behavior was correlated with the Raman strength of the polar modes. (c) 2005 American Institute of Physics.