V. Braccini et al., Transport property characterization of (Ba,La)CuO2/CaCuO2 superconducting multilayers deposited by pulsed laser ablation, SUPERCOND S, 14(8), 2001, pp. 561-566
Superconducting multilayers, whose growth and structure are determined by t
he 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 lay
er phases, both pure (CaCuO2) and doped ((Ba, La)CuO2+delta), that Supply C
uO2 planes and act as charge reservoir blocks, respectively. Oxygen doping,
necessary to bring about superconducting behaviour, also introduces a stro
ng charge unbalance, thus making BaCuO2/CaCuO2 multilayers very unstable. B
y substituting different percentages of La on Ba sites, we tried to stabili
ze the phase. (Ba1-xLaxCuO2+delta)(2)/(CaCuO2)(n) multilayers have been cha
racterized by structural and transport property measurements. Different ele
ctrical properties have been observed by increasing La doping in the block
layer; in particular, 15% La substituted samples show good metallic behavio
ur in the normal state, undergo a superconducting transition at 70 K and pr
esent a low anisotropy, similar to that of YBCO.