We present the synthesis of YBa2Cu3O7-x superconductor oxide with critical temperature - 92 K, by Sol-Gel method. The synthesis of this superconducting compound was performed by using oxalate precursor solution which were prepared by dissolving stoichiometric mixtures of the Y(OOCCH3)•4H2O; Ba(OOCCH3)2 and Cu(OOCCH3)2•H2O acetates in an aqueous solution of oxalic acid, HCOO-COOH. The gel obtained was calcined at 860 oC and then fired at 920 oC in oxidizing atmosphere. The characterization of this superconducting ceramic was performed by x-ray diffraction, micro-Raman spectroscopy and SQUID techniques.

We present the synthesis of YBa2Cu3O7-x superconductor oxide with critical temperature - 92 K, by Sol-Gel method. The synthesis of this superconducting compound was performed by using oxalate precursor solution which were prepared by dissolving stoichiometric mixtures of the Y(OOCCH3)•4H2O; Ba(OOCCH3)2 and Cu(OOCCH3)2•H2O acetates in an aqueous solution of oxalic acid, HCOO-COOH. The gel obtained was calcined at 860 oC and then fired at 920 oC in oxidizing atmosphere. The characterization of this superconducting ceramic was performed by x-ray diffraction, micro-Raman spectroscopy and SQUID techniques.

This work was supported by Fondecyt 11110534 (to M.B.), 1151274 (to M.B.), 11130263 (to C.A.M.W.), Anillo 1107 (to M.B.), and Chile and Fondecyt 196–2013 (to D.G.G.) CONCYTEC, Perú. This research was partially supported by the supercomputing infrastructure of the NLHPC (ECM-02) at Universidad de Chile. A.B. was supported by Conicyt master fellowship 22121199. We gratefully acknowledge Professor Alexander Vologodskii from New York University for helpful comments and advice. Travel for C.B. to and from Chile and Peru was also partially supported by the Howard Hughes Medical Institute, NIH grant R01GM032543, and the U.S. Department of Energy Office of Basic Energy Sciences Nanomachine Program under contract no. DE-AC02-05CH11231.

This work was partially supported by the Consejo Nacional de Ciencia y Tecnologia del Peru (CONCYTEC) through contract No 405-2001-CONCYTEC-OAJ.

This work was partially supported by the Consejo Nacional de Ciencia y Tecno-logía del Perú (CONCYTEC) through contract No 405-2001-CONCYTEC-OAJ.

This work was partially financed by CONCYTEC under contract No. 485-CONCYTEC-OAJ-2004.

We completed the characterization of the superconducting compound [Y1-xCax](BaSr)Cu3-y(PO4)y0zderivativesof YBa2Cu3O7, prepared in normal temperature and pressure conditions by solid state reaction,reported in our previous results. We will show the quantitative results obtained from the analysis by Rietveldmethod of the X-ray diffraction patterns and from magnetic susceptibility measurement in the superconductingregion.

We studied the normal state of the superconducting compound [Y1-xBax](BaSr)Cu3-y(PO4)y0z derivatives of YBa2Cu3O7, prepared in normal temperature and pressure conditions by magnetic susceptibility measurement in the range from 100 to 300K, where we have observed that the compounds followed the Curie-Weiss law behavior. We observed an intimate relationship among Curie-Weiss temperature, effective magnetic moment and oxygen content in the structure.

Driven by the demand to understand and quantify the magnetic properties of superconducting materials, the ac- and dc-magnetic susceptibility has emerged as a valuable technique in the superconductivity field; allowed us to quantify: superconducting critical temperature, Meissner and diamagnetic shielding fractions, Curie constant, Curie-Weiss temperature and effective Bohr magnetón.

In copper oxide superconductor materials the internal charge transference between the superconducting planes of CuO2 and the charge reservoir blocks, it is a key factor that controls the superconducting critical temperature. The superconducting planes of CuO2 are not planes in a strict sense, the position of the Cu(2) atom and the O(2) and O(3) oxygen atoms are not lying in a same plane, the change of its positions are closely related to atomic replacements in the superconducting planes of CuO2 or in the charge reservoir blocks. Therefore, we correlates the substitutions effects in the canonical unit cell of YBa2Cu3O7 with regard to length and angle bond variation of copper and oxygen atoms with the superconducting critical temperature obtained by Rietveld refinement of X-ray diffraction patterns in polycrystalline powder samples, such as: SmBa2Cu3O7, [Y0,90,Pr0,10]Ba2Cu3O7, [Ca,La]Ba2Cu...

A kinetic study of the limonite phase, FeO(OH)-nH2O, was made through X-ray diffraction and u-Raman spectroscopy. The powder oxide was obtained in the Taraco disctrict, Huancané province in the Puno Region, Peru. The goethite phase was identifed by X-ray diffraction as the main minerogical component, after an in situ heat treatment between 100 and 500ºC in an air oxidizing atmosphere and in an inert nitrogen atmosphere. The goethite phase remains stable in the temperature range from room temperature to 200ºC. Between 200ºC and 250ºC there is a phase transition, x-Fe3+O(OH)-->x-Fe2O3, i.e., the pathway from goethite phase to hematite phase, as shown the evolution of the diffraction profiles, Also, the in situ heat treatment u-Raman spectra corroborate the phase transition at 290ºC though the transformation of the characteristic bands of the goethite phase to hematite phase in the...

In the copper oxide superconductor materials the internal charge transference between the superconducting planes of CuO2 and the charge reservoir blocks, it is a key factor that control the superconducting critical temperature. The superconducting planes of CuO2 are not planes in a strict sense, the position of the Cu(2) atom and the O(2), O(3) oxygen atoms are not lying in a same plane, the change of its positions are closely related to atomic replacements in the superconducting planes of CuO2 or in the charge reservoir blocks. Therefore, we correlates the substitutions effects in the canonical unit cell of YBa2Cu3O7 with regard to length and angle bond variation of copper and oxygen atoms with the superconducting critical temperature obtained by Rietveld refinement of x-ray diffraction patterns in polycrystalline powder samples, such as: SmBa2Cu3O7, [Y0.90,Pr0.10]Ba2Cu3O7, [Ca,La]Ba2Cu...

En el presente trabajo se reporta un estudio preliminar sobre la composición mineralógica y la identificación de las fases portadoras de hierro presentes en los peloides de una laguna ubicada en la provincia de Cañete, Lima-Perú. Las técnicas experimentales empleadas en el desarrollo del presente trabajo fueron la difracción de rayos X, espectroscopia Mössbauer por transmisión y fluorescencia de rayos X. Así mismo, se realizaron análisis físico-químicos midiendo el grado de acidez de las muestras. Los resultados obtenidos muestran que en los peloides analizados las fases portadoras del hierro están asociadas a la pirita y al sulfato ferroso. También se detectó la presencia de arcilla tipo bentonita.

In April 2011 took place in the world’s first 100 years of the discovery of superconductivity. Super- conductivity has been the focus of fundamental solid state physics, applied sciences and engineering. Today it is possible to use superconducting materials in a first generation of superconducting devices and in the near future in magnetically levitated trains, superconducting wires, quantum computers, new generation mobile phones, new MRI equipment, etc. The group of superconducting ceramic oxide materials belonging to the UNMSM have studied with great interest the YBa2 Cu3 O7 superconducting material, investigating the incorporation of different cations and anions in different atomic sites in the YBa2 Cu3 O7 structure, as well as derivatives of this structure, to understand their structural, chemical and superconducting properties, then proposing new superconducting compounds. We cel...

En este trabajo se estudia las propiedades estructurales y morfológicas de las películas delgadas de plata de 60 nm de espesor, depositadas sobre sustrato de SiO2 y tratadas térmicamente a distintas temperaturas desde 250 hasta 1000℃. Se ha encontrado que al incrementar la temperatura de recocido, la película de plata se cristaliza en la dirección [111] aumentando la rugosidad superficial y formando islas. Sin embargo, entre la temperatura de recocido de 800 a 900°C se observa un cambio en la orientación preferencial a la dirección [200]. Se discute este cambio de orientación mediante los procesos de difusión.

En el presente trabajo estudiamos la textura de capas superconductoras de YBa2Cu3O7-da través de la difracción de rayos-X. Las capas fueron crecidas sobre el sustrato monocristalino SrTiO3 (100) mediante la deposición de solución química. Posteriormente se sometió la muestra a tratamientos térmicos en una atmósfera oxidante. Una caracterización mediante difracción de rayos-X revela la presencia de reflexiones (00l) para la fase de YBa2Cu3O7-d con una fracción de granos superconductores orientados eje-c del 70%. Mediciones de la Rocking Curves permiten observar 3 regiones texturizadas fuera del plano del sustrato, con valores de FWHM 0.35°; 0.83° y 1.0°.

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.

En el presente trabajo estudiamos la textura de capas superconductoras de YBa2Cu3O7-da través de la difracción de rayos-X. Las capas fueron crecidas sobre el sustrato monocristalino SrTiO3 (100) mediante la deposición de solución química. Posteriormente se sometió la muestra a tratamientos térmicos en una atmósfera oxidante. Una caracterización mediante difracción de rayos-X revela la presencia de reflexiones (00l) para la fase de YBa2Cu3O7-d con una fracción de granos superconductores orientados eje-c del 70%. Mediciones de la Rocking Curves permiten observar 3 regiones texturizadas fuera del plano del sustrato, con valores de FWHM 0.35°; 0.83° y 1.0°.

CNR-CONCYTEC, 2009-2011