CaLaBa superconductor is a protorype of the YBa structure

(PO4)3- doped [Y0.75Ca0.25]SrBaCu3-x(PO4)xOy compounds with 0.00 ≤ x ≤ 0.30 were synthesized using the solid state reaction technique at normal pressure and temperture conditions. The X-ray diffraction patterns show that for x= 0.0 the samples crystallize into an orthorhombic phase, and for other x values the samples presented a tetragonal structure. The Rietveld method was used to refine the lattice constants. The analysis of structure with Rietveld refinement was done using a model that contains one Cu(2) in a four coordination and not in five coordination in the other 123 tetragonal structures. All samples are superconductors as reported previously [1].

[Y1-xCax]SrBaCu2.80(PO4)0.20Oy samples with 0.10 ≤ x ≤ 0.40 were syntherized using the solid state reaction technique. X-ray diffraction patterns show that all the compounds crystallized into a 123 tetragonal structure. The analysis of the structure with Rietveld refinement were made using a model that contains one Cu(2) in four coordination and not in five coordination as in the other 123 tetragonal structures. This fact allows that Tc increase with Ca concentration. All samples are superconductors as reported in a previous paper.

The route by chemical solution deposition to grow textured layers of oxide superconductors has received the most scientific attention over the past two decades. Texture plays a predominant role in the technological applications of superconducting layers. We crystallized a precursor solution of Y, Ba and Cu acetates onto single crystal substrates of perovskite structure by the route of chemical solution deposition and we obtained textured superconducting layers of YBa2Cu3O7. We divided our results in two parts: a) We review the epitaxial growth of YBa2Cu3O7 superconducting layers through physical and chemical methods, and b) We study mainly the epitaxial growth of YBa2Cu3O7 superconducting layers by X ray diffraction.

Y Ba2Cu3O7 epitaxial superconducting film is consequence of an optimum epitaxial growth process of superconducting grains. Also, the substrate's epitaxy has a direct repercussion on the lm microstructure and its physical properties. Conventional characterization techniques such as: scanning electronic microscopy, and x ray difrraction, allowed us to obtain a quick assessment of epitaxy quality through of texture quantification of the film. We present the results of texture quantification in Y Ba2Cu3O7 superconducting films.

We studied the optimun temperature to favor the epitaxial growth of YBa2Cu3O7 layers using threesintering temperatures of 820, 840 and 860℃, by the chemical solution deposition method in SrTiO3[100] monocrystalline substrates. Surface morphology was obtained by optical imaging, which qualitativelycharacterize the homogeneity and the grain presence along the c-axis. The X-ray diffractionconfirms the preferential epitaxial growth (00l) of the YBa2Cu3O7 crystals, resulting in a higher intensityof the profiles (00l) for the temperature of 860℃. The samples shown superconducting behaviourat critical temperature of 90 K, for the three cases.