OUT-OF-PLANE PSEUDOGAP IN Bi2Sr2CaCu2Oy THIN FILMS GROWN ON SrTiO3 VICINAL SURFACES

Abstract

The out-of-plane resistivity ρc(T) is measured for Bi 2 Sr 2 CaCu 2 O 8 superconducting thin films successfully deposited by in situ magnetron RF–sputtering on vicinal (100) SrTiO 3 substrates. Oriented film with c-axis inclined with respect to the basal plane by a tilt angle α≈4° was obtained. The oxygen content of the film was changed from maximally overdoped state to strongly underdoped nonsuperconducting states. It was found that the temperature corresponding to the minimum between metallic and semiconductive behavior appears to reflect the opening of the pseudogap for transport along c-axis. We found that the opening of the pseudogap along c-axis does not coincide with pseudogap seen in ab plane.