Structure and Dielectric Behavior of Epitaxially Grown SrTiO3Film between YBa2Cu3O7-δElectrodes

To obtain a high insulating SrTiO 3 layer, the parallel capacitors of epitaxially grown YBa 2 Cu 3 O 7-δ / SrTiO 3 / YBa 2 Cu 3 O 7-δ have been fabricated by a Chemical Mechanical Planarization method. The dielectric constant and tan δ of the SrTiO 3 film at 2.2 K was 27000 and 0.027 at 10 kHz, respectively. The temperature variation of the dielectric constant could be well fitted by the formulae of Curie-Weiss and Barrett in the temperature ranges above 100 K and 30< T <100 K, respectively. The best-fit parameters were coincident with those for SrTiO 3 single crystals. In order to examine the influence of degraded SrTiO 3 layers at the YBa 2 Cu 3 O 7-δ /SrTiO 3 interfaces on the dielectric constant, a multilayer model involving two kind of SrTiO 3 layers with different dielectric characteristics was proposed. The results revealed that the degraded SrTiO 3 layer is very thin and the dielectric constant of the SrTiO 3 film was dominated by that of single-crystal-like SrTiO 3 layer.