Epitaxial growth of Dy‐Ba‐Cu‐O superconductor on (100)SrTiO3 using reactive and activated reactive evaporation processes

Epitaxial and highly oriented thin films of Dy‐Ba‐Cu‐O superconductor have been grown by thermal evaporation of Dy, Ba and Cu metals onto MgO and SrTiO3 substrates. Oxidation of the evaporated metal species is realized by releasing oxygen gas near the substrate during evaporation. The films deposited on (100)SrTiO3, when annealed at 900 °C, crystallize epitaxially with c‐axis on the plane of the substrate. These films are metallic with superconducting transition width ∼1.5 K. On magnesium oxide substrates, the film crystallize into a polycrystalline material which undergoes a strong c‐axis reorientation upon further annealing at 950 °C. Activated Reactive Evaporation process has been successfully used for in situ growth of the superconducting phase on Al2O3 substrates. These films reach a zero resistance state at 60 K.