DEPOSITION OF (Ba, La)CuO2/CaCuO2 SUPERCONDUCTING MULTILAYERS BY PULSED LASER ABLATION

Abstract

Superconducting multilayers, whose growth and structure are determined by the kinetic deposition instead by thermodynamics, are a powerful tool for investigating high T c superconductors (HTSC) properties. By means of Pulsed Laser Deposition (PLD), we grew such materials alternating infinite layer phases both pure and doped, to supply CuO 2 planes and charge reservoir (CR) blocks respectively. We found out that using chemically doped CR leads to a semiconducting behavior, whereas oxygen doping seems to be much more effective, since the BaCuO 2 infinite phase, grown in high oxygen partial pressure, does actually bring about a superconducting behavior. We deposited BaCuO 2/ CaCuO 2 superlattices with various periodicities and studied their transport and structural properties. By varying the deposition parameters, we reached both kinetic and thermodynamic growth and we observed semiconducting and superconducting behaviors.