Multimode quantitative scanning microwave microscopy of in situ grown epitaxial Ba1-xSrxTiO3 composition spreads

We have performed variable-temperature multimode quantitative microwave microscopy of in situ epitaxial Ba1-xSrxTiO3 thin-film composition spreads fabricated on (100) LaAlO3 substrates. Dielectric properties were mapped as a function of continuously varying composition from BaTiO3 to SrTiO3. We have demonstrated nondestructive temperature-dependent dielectric characterization of local thin-film regions. Measurements are simultaneously taken at multiple resonant frequencies of the microscope cavity. The multimode measurements allow frequency dispersion studies. We observe strong composition-dependent dielectric relaxation in Ba1-xSrxTiO3 at microwave frequencies. (C) 2001 American Institute of Physics.