Información del autor
Autor Piqueras de Noriega, Javier |
Documentos disponibles escritos por este autor (322)
texto impreso
Electrically active defects in epitaxial, n-type, 4H-SiC have been investigated by electron-beam-induced current (EBIC) in the scanning electron microscope. Several defects, mainly nanopipes, 6H polytype inclusions and triangular, carrot-like, d[...]texto impreso
Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Tomashpolsky, Y. Y. ; Sadovskaya, N. V. | Springer | 1997-04Bi_2Sr_2CaCu_2O_(8+x) superconducting ceramics have been irradiated in the scanning electron microscope (SEM), and the irradiation-induced effects investigated by cathodoluminescence (CL), secondary electron emission (SEE) and X-ray microanalysi[...]texto impreso
Sochinskii, N. V. ; Dieguez, E. ; Pal, U. ; Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Agullorueda, F. | IOP publishing ltd | 1995-06Undoped and doped CdTe wafers have been thermally annealed in Ga melt, or in Cd vapour or in a vacuum to eliminate Te precipitates from the volume of the wafers. The effect of annealing conditions on the transformation of Te precipitates has bee[...]texto impreso
Bazta, Otman ; Urbieta Quiroga, Ana Irene ; Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Addou, M. ; Calvino, J.J. ; Hungría, A.B. | Elsevier Science SA | 2019-11-05Pure ZnO and ZnO: 2%Y:x%Li (x = 0, 3, 5 and 7 at.%) thin films have been successfully prepared onto glass substrates under optimized conditions by spray pyrolysis technique at 450 ºC and their suitability for the fabrication of efficient optoele[...]texto impreso
Plaza, J. L. ; Hidalgo Alcalde, Pedro ; Piqueras de Noriega, Javier ; Dieguez, E. | Sociedad Española de Cerámica y Vidrio | 2000-07En este trabajo se ha realizado el estudio de cristales de GaSb crecidos por el método Bridgman y dopados con Er y Nd con distintas concentraciones. Se han realizado análisis de absorción atómica pudiéndose obtener el coeficiente de segregación [...]texto impreso
Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Garcia, J. A. | IOP publishing ltd | 2009-03-18Cathodoluminescence and photoluminescence techniques have been used to investigate room temperature light emission from ß-Ga_2O_3:Eu nanostructures, which were obtained by two methods. In one of them, a mixture of Ga_2O_3/Eu2O3 powders was used [...]texto impreso
Piqueras de Noriega, Javier ; Díaz-Guerra Viejo, Carlos ; Vila Santos, María | American Institute of Physics | 2010-05-10Exchange anisotropy has been observed and investigated in single-crystalline CuO nanowires grown by thermal oxidation of Cu. The exchange bias field decreases by increasing temperature and can be tuned by the strength of the cooling field. A tra[...]texto impreso
Miroiu, F. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Wiley-V C H Verlag Gmbh | 2006Fabrication of low dimensional structures of II-VI compounds as nanoparticles and elongated structures, such as nanowires or nanotubes, is a subject of increased interest due to their potential use in different technological applications. The ai[...]texto impreso
Piqueras de Noriega, Javier ; Alemán Llorente, Belén ; Ortega Villafuerte, Yanicet ; García Martínez, José Ángel | American Institute of Physics | 2011-07-01Fe dopedZnO nanowires,nanorods, and urchin-like nanostructures have been grown using an evaporation-deposition method with compacted mixtures of ZnS and Fe_2O_3 powders, with different Fe contents as precursors. Treatments at 950 °C under argon [...]texto impreso
López, Iñaki ; Nogales Díaz, Emilio ; Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Wiley-V C H Verlag Gmbh | 2012-01The field emission properties of gallium oxide nanowires grown by thermal evaporation-deposition have been investigated inside the chamber of a scanning electron microscope. Turn on electric fields and enhancement factors have been determined fo[...]texto impreso
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | IOP publishing ltd | 2006-03-28Samples of rutile TiO2 have been prepared by sintering compacted powders under argon flow. Long (above 20 h) sintering times at 1500 degrees C led to the formation of rods with squared cross-sections in a broad range of sizes. A two-step anneali[...]texto impreso
Díaz-Guerra Viejo, Carlos ; Almodóvar, P. ; Camacho López, M. ; Camacho López, S. ; Piqueras de Noriega, Javier | Elsevier Science SA | 2017-10-05The formation of different phases of Bi?O? induced by laser irradiation of Bi films has been assessed in situ by micro-Raman spectroscopy as a function of laser wavelength, power density and irradiation time. Raman mapping of the irradiated samp[...]texto impreso
Storgards, J. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Chenot, M. ; Dimroth, F. ; Bett, A.V. | IOP publishing ltd | 2004-07The effect of electrochemical etching of n-type GaSb in aqueous solutions of HCl and HF has been analysed. By anodization in HCl, two different morphologies of porous layers were observed depending on the current density. At low current density [...]texto impreso
López, I. ; Castaldini, A. ; Cavallini, A. ; Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2014-10-15The behaviour of ß-Ga?O? nanowires as photoconductive material in deep ultraviolet photodetectors to operate in the energy range 3.0-6.2 eV has been investigated. The nanowires were grown by a catalyst-free thermal evaporation method on gallium [...]texto impreso
Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2005-11Thermal treatment of compacted GeO_2 powder under argon flow leads to the growth of a dense distribution of microwires and nanowires on the sample surface. Extended treatment causes the formation of more complex structures, including arrays of n[...]texto impreso
Hidalgo Alcalde, Pedro ; Liberti, Emanuela ; Rodriguez lazcano, Yamilet ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2009-10-01GeO_2 nanowires doped with Eu, Er, or Mn, as well as codoped with each of these ions and Sri, have been grown by a catalyst-free vapor-solid process. The incorporation of Sri has been found, in all cases, to favor the formation of straight wires[...]texto impreso
Ortega Villafuerte, Yanicet ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Amer Scientific Publishers | 2010-01Rare-earth (RE) ions are widely investigated luminescent centers because their intraionic-4f transitions generate narrow and intense emission lines. In this work Eu doped ZnO nanoneedles have been grown, by a thermal evaporation-deposition metho[...]texto impreso
Sochinskii, N. V. ; Saucedo, E. ; Abellan, M. ; Rodríguez Fernández, José ; Hidalgo Alcalde, Pedro ; Piqueras de Noriega, Javier ; Ruiz, C.M. ; Bermudez, V. ; Dieguez, E. | Elsevier Science BV | 2008-04Cadmium telluride (CdTe) crystals and epitaxial layers were grown by the vertical Bridgman method and vapor-phase epitaxy, respectively, to obtain the high-resistive material suitable for X- and gamma-ray detectors. The crystals and layers were [...]texto impreso
Piqueras de Noriega, Javier ; Ryu, Y. K. ; Fernández Sánchez, Paloma | Wiley-V C H Verlag Gmbh | 2011-04Er-doped ZnO nano- and microstructures have been grown by thermal treating of compacted mixtures of ZnO and Er_2O_3 powders and their optical properties have been studied by cathodoluminescence (CL). Annealing the pressed samples leads to the gr[...]texto impreso
Herrera, Manuel ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2013-05-02Undoped and Mn doped SnO_2 nanowires, nanobelts, and microplates have been grown by a thermal evaporation method that enables the morphology and the Mn content in the structures to be controlled. The structural and morphological characterization[...]texto impreso
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | American Institute of Physics | 2005Micro- and nanotubes, and other elongated structures of SnO_2 as wires and rods, were grown after sintering in argon flow at temperatures ranging from 1350 degrees C to 1500 degrees C. The morphology and luminescence properties of these structur[...]texto impreso
Magdas, D.A. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Amer Inst Physics | 2006-03-13Indium oxide elongated micro- and nanostructures have been grown by thermal treatment of InN powder. Chains of nanopyramids connected by nanowires, forming a necklace-like structure, as well as cubes and arrow-like structures consisting of a lon[...]texto impreso
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Gregoratti, Luca ; Piqueras de Noriega, Javier | Amer Scientific Publishers | 2008-12Titanium oxide nanowires have been grown by thermal treatment of pressed TiN powder under argon or N-2 flow. It has been found that two-step treatments at two different temperatures, 400 degrees C and 800 degrees C, lead to the growth of nanowir[...]texto impreso
Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Trans Tech Publications Ltd | 2008Sintering of a ZnO-MgO powder mixture under argon flow leads to the growth of elongated Mg doped ZnO structures such as stacks of nanoplates and rods with secondary nanowires in a comb-like arrangement. The nanoplates grow perpendicular to a cen[...]texto impreso
Ortega Villafuerte, Yanicet ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | IOP publishing ltd | 2007-03-21Sintering of a ZnO-SnO_2 mixture under argon flow leads to the growth of microrods on the sample surface, which are formed by oriented stacks of nanoplates. Energy dispersive spectroscopy and cathodoluminescence ( CL) in the scanning electron mi[...]