The LaCaBaCu2.80(X)0.20(O)7-δ compound with X=(P04)^(3-) and (BO3)^(3-) has been prepared by a solid state reaction method and we compare the resulting structures. phase formation and CriticaL Temperatures (Tc's) with the well known LaCaBaCu3(O)7-δ (La1113) superconductor. For both cases, the X-ray diffractogram revealed the BaCuO2 and CuO as extra phases; this is confirmed by SEM, EDX and HAEM. The Rietveld analysis suggested orthorhombic crystalline structures belonging to the Pmmm spatial group with a=3.849Å, b=3.880Å and c=11.630Å to the LaCaBaCu2.80(P04)0.20(O)7-δ, and a=3.884Å b=3.890Å and C=11.640Å to the LaCaBaCu2.80(BO3)0.20(O)7-δ. Tc's were calculated from the derivativa of magnetic susceptibility plots by using a SQUID detection system, these indicated the Tc's are 86K and 55K to the LaCaBaCu2.80(P04)0.20(O)7-δ and the LaCaBaCu2.80(BO3)0.20(O)7-δ respectively.

The LaCaBaCu2.80(X)0.20(O)7-δ compound with X=(P04)^(3-) and (BO3)^(3-) has been prepared by a solid state reaction method and we compare the resulting structures. phase formation and CriticaL Temperatures (Tc's) with the well known LaCaBaCu3(O)7-δ (La1113) superconductor. For both cases, the X-ray diffractogram revealed the BaCuO2 and CuO as extra phases; this is confirmed by SEM, EDX and HAEM. The Rietveld analysis suggested orthorhombic crystalline structures belonging to the Pmmm spatial group with a=3.849Å, b=3.880Å and c=11.630Å to the LaCaBaCu2.80(P04)0.20(O)7-δ, and a=3.884Å b=3.890Å and C=11.640Å to the LaCaBaCu2.80(BO3)0.20(O)7-δ. Tc's were calculated from the derivativa of magnetic susceptibility plots by using a SQUID detection system, these indicated the Tc's are 86K and 55K to the LaCaBaCu2.80(P04)0.20(O)7-δ and the LaCaBaCu2.80(BO3)0.20(O)7-δ respectively.

The present work is the study of the different methods used to determine the toxicity produced by the presence of a contaminating metal in the blood. Mainly, the presence of lead in the blood was taken as a reference to focus the work, knowing that metals like Cadmium (Cd) and Mercury (Hg) are also toxic to health and the environment. Although the information is extensive on the methods to be studied and in some cases it is not detailed to define each process, a comparative study of the most relevant and currently used methods can be carried out, taking into account that the choice will be defined according to the main characteristics of each one. Although all agree to be electrochemical processes, there are details to know which method to choose, either by sensitivity, economic or even structural factors, such as having a laboratory for its development. Environmental pollution with toxi...

It is known the YBa2Cu30H (Yl23) prepared by the solid reaction method coexists with a green phase Y2BaCu05 (Y211). In this work we study the behavior of the Y211 (pure) overheated at 11 00°C and 1300°C respectively. The starting sample was prepared by the conventional solid reaction method using appropriate amounts of Y203, BaC03 and CuO; the initial sample was green in color. From the X ray diffractogram (XRD) and using the Rietveld refinement we found that the crystalline structure is orthorhombic and belong to the Pnma spatial group. This is the sorne structure as the one found by Michael and Raveau 1 • The starting sample was overheated at 11 00°C under oxygen pressure of 0.1 atm. According with the XRD, there are no significant variations on its structure. Nevertheless after an overheating of 1300°C in the same oxygen pressure, a new phase Y203 with a cubic symmetry together ...

In this work we report the structural and electronic properties of the compound [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) which is a superconductor below the critical temperature TC = 80 K. This compound was prepared using the Sol-Gel method. The structural properties were studied by X-ray diffraction and electronic properties were studied by X-ray Photoemission Spectroscopy (XPS). The results were compared with those ones of the traditional superconductor YBa2Cu3O7-δ (YBCO). The X-ray photoemission spectra were taken at room temperature (normal state) and at 30 K (superconductor state). In the superconductor state, the X-ray photoemission spectra showed a shift in the O 1s. While the position of the Cu3p principal peaks do not change when measuring at 30 K. However, the spectra reveal the appearance of a new peak due to de hybridization of the Cu3d and O2p states. In addition, the Fou...

En este trabajo se reporta las propiedades estructurales y electrónicas del compuesto [Y0.8Ca0.2](Ba0.5Sr0.5)2Cu3O7-δ (YCaBaSr) que es superconductor con temperatura crítica TC = 80 K. El compuesto fue preparado mediante el método Sol-Gel. Las propiedades estructurales y electrónicas de este compuesto se estudiaron mediante difracción de rayos X (DRX) y espectroscopia de fotoemisión de rayos X (XPS) respectivamente. Los resultados fueron comparados con los del superconductor tradicional YBa2Cu3O7- δ (YBCO). Las medidas por XPS se realizaron a temperatura ambiente (en el estado normal) y a 30 K (estado superconductor). En el estado superconductor, los espectros XPS de ambos compuestos muestran corrimiento en el pico O 1s. Mientras que, la posición de los picos principales del Cu 3p no cambian de posición al ser medidos a 30 K y 293 K. Sin embargo, se observa en el espectro la ap...