THICKNESS DEPENDENCE OF DIELECTRIC LOSS IN SRTIO3 THIN-FILMS

We have measured the dielectric loss in SrTiO3 thin films grown on SrR uO3 electrode layers with thickness ranging from 25 nm to 2.5 mu m. Th e loss depends strongly on the thickness but differently above and bel ow T approximate to 80 K: as the thickness increases, the loss decreas es at high temperatures but becomes higher at low temperatures. Our re sult suggests that, in the high temperature regime, the interfacial de ad layer effect dominates while, in the low temperature regime, the lo sses related to the structural phase transition and quantum fluctuatio ns are important. (C) 1998 American Institute af Physics.