Epitaxial Y-Ba-Cu-O films on Si with intermediate layer by rf magnetron sputtering

Abstract

Epitaxial films of Y-Ba-Cu-O were obtained on a Si substrate, using an epitaxial intermediate layer consisting of BaTiO3(or SrTiO3)/MgAl2O4. MgAl2O4 was epitaxially grown on the Si(100) substrate by chemical vapor deposition. Then, SrTiO3 or BaTiO3 was also epitaxially grown on the MgAl2O4 layer by means of rf magnetron sputtering. Epitaxial Y-Ba-Cu-O films were prepared on BaTiO3(SrTiO3)/MgAl2O4/Si substrates by rf magnetron sputtering. Preparation of an Y-Ba-Cu-O film directly on MgAl2O4/Si was also studied, but only a randomly oriented polycrystalline film has been obtained so far. Resistive superconducting transitions with zero resistance at 65 K on SrTiO3/MgAl2O4/Si and at 70 K on BaTiO3/MgAl2O4/Si were observed.