NEAR SINGLE CRYSTAL-LEVEL DIELECTRIC LOSS AND NONLINEARITY IN PULSED-LASER DEPOSITED SRTIO3 THIN-FILMS

We present low-frequency dielectric loss and nonlinearity measurements in SrTiO3 thin films grown by pulsed laser deposition on SrRuO3 elect rode layers. A low loss tangent in the order of 10(-4) close to the le vel found in SrTiO3 single crystals, was observed. Combined with a lar ge tunability, this resulted in a figure of merit for frequency and ph ase agile materials that can rival that observed in single crystals. T he result is potentially significant for tunable microwave device appl ications, and it points to stress and interface effects as the possibl e causes for higher dielectric losses in thin films. (C) 1998 American Institute of Physics.