Growth of HgBa 2CaCu 2O x thin films using seed-buffer layers of YBa 2Cu 3O y

Abstract

High quality superconducting HgBa 2CaCu 2O x (Hg-1212) thin films have been fabricated on SrTiO 3 (STO) substrates using YBa 2Cu 3O y (YBCO) as a seed-buffer layer (SBL). X-Ray diffraction indicates that the Hg-1212 thin films have a c-axis epitaxial structure with (100) Hg-1212//(100) STO. The φ-scans and rocking curves demonstrate that the SBL results in a better orientation of the Hg-1212 films. Scanning electron microscopy (SEM) also shows that the film surfaces are more regular. The Hg-1212 thin films on YBCO SBL have a superconducting transition temperature T c =115–124 K and a critical current density J c >1×10 6 A/cm 2 at 77 K in zero field.