Transport property characterization of (Ba,La)CuO2/CaCuO2 superconducting multilayers deposited by pulsed laser ablation

Superconducting multilayers, whose growth and structure are determined by the kinetic deposition instead of by thermodynamics, are a powerful tool for investigating high T-c superconductor properties. By means of pulsed laser deposition, we grew superconducting superlattices alternating infinite layer phases, both pure (CaCuO2) and doped ((Ba, La)CuO2+delta), that Supply CuO2 planes and act as charge reservoir blocks, respectively. Oxygen doping, necessary to bring about superconducting behaviour, also introduces a strong charge unbalance, thus making BaCuO2/CaCuO2 multilayers very unstable. By substituting different percentages of La on Ba sites, we tried to stabilize the phase. (Ba1-xLaxCuO2+delta)(2)/(CaCuO2)(n) multilayers have been characterized by structural and transport property measurements. Different electrical properties have been observed by increasing La doping in the block layer; in particular, 15% La substituted samples show good metallic behaviour in the normal state, undergo a superconducting transition at 70 K and present a low anisotropy, similar to that of YBCO.