Epitaxial growth of YBa2Cu3O7−δ films on oxidized silicon with yttria- and zirconia-based buffer layers

Abstract
A study of epitaxial growth of YBa2Cu3O7−δ films on oxidized Si with yttria- and zirconia-based buffer layers is reported. Using substrates with either SiO2 free or naturally oxidized (100) surfaces of Si it was found that a thin SiO2 layer on top of the Si favors high-quality superconducting film formation. Compared to yttria-stabilized ZrO2 (YSZ) single layers, YSZ\Y2O3 double and YSZ/Y2O3\YSZ triple layers allows the deposition of thin YBa2Cu3O7−δ films with improved properties including reduced aging effects. In epitaxial YBa2Cu3O7−δ films grown on the double buffer layers a critical temperature Tc(R=0)=89.5 K and critical current densities of 3.5×106 A/cm2 at 77 K and 1×107 A/cm2 at 66 K were reached.