Información del autor
Autor Piqueras de Noriega, Javier |
Documentos disponibles escritos por este autor (322)
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Maestre Varea, David ; Martínez Velasco, I. ; Cremades Rodríguez, Ana Isabel ; Amati, M. ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2010-07-15Mn-doped In(2)O(3) nanopyramids have been grown by a catalyst-free thermal process at 700 degrees C using InN and Mn(2)O(3) powders as precursors. Energy dispersive spectroscopy, as well as X-ray photoelectron spectroscopy, demonstrate the prese[...]texto impreso
Cebriano Ramírez, Teresa ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Elsevier Science SA | 2012-08-15Sb_2O_3 micro- and nanostructures of the face centered cubic phase, have been grown by a catalyst free evaporation deposition method with powder of metallic Sb as precursor. Nanopyramids, octahedra and nanorods are the building blocks of complex[...]texto impreso
Pereira, L. ; Pereira, E. ; Gomes, H. ; Rodrigues, A. ; Rees, A. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Elsevier Science SA | 2000-04The properties of microelectrical conduction in microwave plasma assisted chemical vapour deposition (MPCVD) diamond films were investigated using an atomic force microscopy probe, giving a morphological map of the electrical conduction with a s[...]texto impreso
Castaldini, A. ; Cavallini, A. ; Fraboni, B. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | American Physical Society | 1997-12-15We study, by cathodoluminescence and junction spectroscopy methods, the deep traps located near midgap in semiconducting and semi-insulating II-VI compounds, namely, undoped CdTe, CdTe:Cl, and Cd0.8Zn0.2Te. In order to understand the role such d[...]texto impreso
Alonso Orts, Manuel ; Nogales Díaz, Emilio ; San Juan, J. M. ; Nó, M. L. ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Amer Physical Soc | 2018-06-07Optical microcavities are key elements in many photonic devices, and those based on distributed Bragg reflectors (DBRs) enhance dramatically the end reflectivity, allowing for higher quality factors and finesse values. Besides, they allow for wi[...]texto impreso
Maestre Varea, David ; Haeussler, Dietrich ; Cremades Rodríguez, Ana Isabel ; Jaeger, Wolfgang ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2011-04In_2O_3 nanorods have been grown by a catalyst free evaporation-deposition method. Transmission electron microscopy (TEM) investigations reveal that the rods contain tubular cavities, herein referred to as "nanopipes", along the total length of [...]texto impreso
Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Vasco, E. ; Zaldo, C. | natl Inst Optoelectronics | 2004-03Scanning tunnelling microscopy and spectroscopy have been used to characterize electrically active grain boundaries in pulsed laser deposited ZnO films with grain sizes in the range 216-500 nm. The p-type behaviour at the boundary is evidenced b[...]texto impreso
Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Urbieta Quiroga, Ana Irene | Elsevier Science SA | 2012-02-15Mn doped ZnO nano- and microstructures have grown by a catalyst free evaporation-deposition method. Different morphologies such as nanowires, nanorods and stacks of nanoplates with a skewer arrangement around a central rod, have been obtained. S[...]texto impreso
Dutta, P. S. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dieguez, E. ; Bhat, H. L. | Amer Inst Physics | 1996-07-15Diffusion of tellurium In undoped p-GaSb has been carried out. Using the cathodoluminescence and photoluminescence techniques, the luminescence centers in Te-diffused samples have been identified and compared with the Te-doped bulk GaSb. Fundame[...]texto impreso
The contactless modulation spectroscopy technique of photoreflectance (PR) has been used to study the near band edge transitions in CdTe, CdTe:V and CdTe:Ge bulk crystals in the range of 14 and 400 K for the first time. The lineshape of the PR[...]texto impreso
Nogales Díaz, Emilio ; Joachimsthaler, I. ; Heiderhoff, R. ; Piqueras de Noriega, Javier ; Balk, L.J. | American Institute of Physics | 2002-07-15Near-field cathodoluminescence (NFCL) has been used to characterize hydride vapor phase epitaxy grown n-GaN films. This technique can obtain high resolution luminescence images and perform local measurements of the diffusion length for minority [...]texto impreso
Piqueras de Noriega, Javier ; Vila Santos, María ; Díaz-Guerra Viejo, Carlos | IOP publishing ltd | 2010-04-07CuO nanostructures with different morphologies, such as single-crystal nanowires, nanoribbons and nanorods, have been grown by thermal oxidation of copper in the 380–900?°C temperature range. Cathodoluminescence spectra of the nanostructures sho[...]texto impreso
Cremades Rodríguez, Ana Isabel ; Albrecht, M. ; Ulloa, J.M. ; Piqueras de Noriega, Javier ; Strunk, H.P. ; Hanser, D. ; Davis, R. F. | Materials Research Society | 2000A series of 100 nm thick InGaN films with In content up to 14% has been grown by MOVPE on SiC substrates. Optical characterization was carried out by means of reflectance spectrometry, photoluminescence and cathodoluminescence. Optical propertie[...]texto impreso
Herrera Zaldiva, M. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Sukhoveyev, W. ; Ivantsov, V. A. ; Shreter, Y. G. | Springer | 2000-07Cathodoluminescence (CL) in the scanning electron microscope has been applied to study the luminescence emission of GaN single crystals grown by LPE methods. CL spectra show the presence of near band edge and of yellow emissions. The latter has [...]texto impreso
Vásquez, G. C. ; Karazhanov, S. Zh. ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Foss, S. E. | American Physical Society | 2016-11-23The effects of doubly ionized oxygen vacancies [(V_O)ˆ(2+)]on the electronic structure and charge distribution in rutile TiO_2 are studied by combining first-principles calculations based on density functional theory and experimental results fro[...]texto impreso
Panin, G. N. ; Dutta, P. S. ; Piqueras de Noriega, Javier ; Dieguez, E. | Amer Inst Physics | 1995-12-11Inversion in conductivity type of GaSb from p- to n- has been observed as a result of argon ion beam milling. Electron beam induced current (EBIC) measurements have been employed for detecting the type conversion. Enhancement in the luminescence[...]texto impreso
Dutta, P. S. ; Sreedhar, A. K. ; Bhat, H. L. ; Dubey, G. C. ; Kumar, V. ; Dieguez, E. ; Pal, U. ; Piqueras de Noriega, Javier | American Institute of Physics | 1996-03-15Passivation of point and extended defects in GaSb has been observed as a result of hydrogenated amorphous silicon (a-Si:H) treatment by the glow discharge technique. Cathodoluminescence (CL) images recorded at various depths in the samples clear[...]texto impreso
Monteiro, T. ; Pereira, E. ; Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | Electrochemical Soc Inc | 1993-12Time resolved photoluminescence (TRPL) of untreated and heat-treated n-type GaP:S samples has been investigated and compared with data from cathodoluminescence in a scanning electron microscope (CL-SEM). Special attention is given to broad emiss[...]texto impreso
Plaza, J. L. ; Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dieguez, E. | Elsevier Science SA | 2000-02-14In this work several changes induced by polishing, chemical etching and thermal treatment in the properties of Er- and Nd-doped GaSb substrates with different doping levels grown by the vertical Bridgman method have been studied. The analysis ha[...]texto impreso
Monaico, E. ; Ursaki, V. V. ; Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Boyd, R. W. ; Tiginyanu, I. M. | IOP publishing ltd | 2004-12Porous CdSe layers have been produced by anodic etching of crystalline substrates in a HCl solution. Anodization under in situ. UV illumination resulted in the formation of uniformly distributed parallel pores with a diameter of 30 nm, stretchin[...]texto impreso
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Fernández Sánchez, Paloma ; Solís, J. ; Piqueras de Noriega, Javier | natl Inst Optoelectronics | 2000-09Pulsed laser treatments in air and in vacuum have been performed in CdTe wafers. The laser induced changes have been monitored by emissive mode and cathodoluminescence (CL) in a scanning electron microscope. Remarkable differences between the ef[...]texto impreso
Gonzalo, A. ; Nogales Díaz, Emilio ; Lorenz, K. ; Víllora, E. G. ; Shimamura, K: ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Elsevier Science BV | 2017-11The structural and luminescence properties of gallium oxide nanowires doped with chromium or manganese have been investigated. Undoped Ga?O? nanostructures have been fabricated by a thermal evaporation method, while doping was subsequently achie[...]texto impreso
Iribarren, A. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Wiley-V C H Verlag Gmbh | 2014-03Cathodoluminescence (CL) of Te doped elongated ZnO microstructures obtained by a vapour-solid (V-S) technique has been investigated. The CL intensity changes along the microstructures axis are related to the gradient of Te content, which influen[...]texto impreso
Nogales Díaz, Emilio ; García, José A. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | American Institute of Physics | 2007-02-01Red luminescence emission from chromium doped ß-Ga_2O_3 nanowires has been studied by means of photoluminescence (PL) techniques. PL excitation shows several bands in the ultraviolet-visible region. Time decay values, obtained by time resolved P[...]texto impreso
Rodríguez Fernández, J. ; Carcelen, V. ; Hidalgo Alcalde, Pedro ; Vijayan, N. ; Piqueras de Noriega, Javier ; Sochinskii, N. V. ; Pérez, J. M. ; Dieguez, E. | Amer Inst Physics | 2009-08-15Cadmium zinc telluride, CdZnTe, bulk single crystals doped with 10^19 at./cm^3 of indium in the initial melt were grown by vertical Bridgman technique. The samples were investigated by energy dispersive spectroscopy, cathodoluminiscence (CL), an[...]texto impreso
Remote electron beam induced current (REBIC) measurements have been carried out to investigate electrically active regions in YBa_2Cu_3O_(7-x) single crystals. Enhanced REBIC contrast, found in growth steps and other topographic features of the [...]texto impreso
García, J.A. ; Plugaru, R ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Tate, T. J. | Cambridge Univ Press | 2004-07The luminescence of amorphous silicon layers either implanted with Er or co-implanted with Er and O has been studied by photoluminescence (PL) and cathodoluminescence (CL) in the scanning electron microscope. Annealing in nitrogen causes the for[...]texto impreso
Cebriano Ramírez, Teresa ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Springer | 2013-05Sb_2O_3 microrods of the orthorhombic phase have been grown by evaporation deposition with Sb powder as precursor. The rods, of rectangular cross section, are composed of weakly bonded stacks of tiny plates of few hundreds of nanometres, which s[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | American Institute of Physics | 1989-09-15Polycrystalline GaP and InP have been observed by scanning electron acoustic microscopy. While grain boundaries show a weak contrast, twinned regions are clearly revealed. Results suggest that the contrast observed is related to signal generatio[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Pergamon-Elsevier Science Ltd | 1993-09The temperature dependence of scanning electron acoustic microscopy (SEAM) and cathodoluminescence signals of B_i2Sr_2CaCu_2O_x samples have been measured. The evolution of SEAM signal with temperature between 90 and 300 K indicates the capabili[...]texto impreso
Some scanning electron acoustic microscopy (SEAM) applications to the characterization of electronic materials are discussed. The specific problem of the observation of dislocations and dislocation-related features in GaAs is treated as an examp[...]texto impreso
Dislocation lines in {110} sections of In-doped GaAs are imaged by scanning electron acoustic microscopy (SEAM). Cathodoluminescence measurements show the presence of a high indium concentration at dislocations. It is proposed that the semi-insu[...]texto impreso
Urchulutegui, M. ; Piqueras de Noriega, Javier ; LLopis, J. | American Institute of Physics | 1989-04-01The capability of scanning electron?acoustic microscopy in the characterization of MgO crystals has been studied. The conditions for the observation of different surface and subsurface features in as?grown and deformed crystals are described and[...]texto impreso
Urbieta Quiroga, Ana Irene ; Piqueras de Noriega, Javier ; Muñoz, V. | Elsevier Science SA | 2000-12-15ZnSe single crystals were grown from n-type microcrystalline boules by a Solid Phase Recrystallization (SPR) method. The recrystallizations were performed under different atmospheres, Ar or Se, and pressures to investigate the influence of growt[...]texto impreso
Urbieta, C. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Muñoz, V. | Elsevier Science SA | 2001-03-22ZnSe single crystals were grown from n-type microcrystalline boules by :I solid phase recrystallization (SPR) method. During. SPP,. twinned regions appear with different electronic recombination properties. The recrystallizations were performed [...]texto impreso
Urbieta, S. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Vasco, E. ; Zaldo, C | Wiley-V C H Verlag Gmbh | 2003-01Highly (001) textured ZnO films grown on (100)InP by pulsed laser deposition have been studied by Scanning Tunneling Microscopy (STM). Constant current images show a well defined grain structure, which allows to perform local spectroscopic studi[...]texto impreso
Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dutta, P: S. ; Dieguez, E. | American Physical Society | 1999-10-15V- and Ru-doped GaSb crystals have been investigated by scanning tunneling spectroscopy in a combined scanning electron microscope-scanning tunneling microscope system. Local variations of surface band gap have been measured with high spatial re[...]texto impreso
Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plaza, J. L. ; Dieguez, E. | American Institute of Physics | 1999-08-01Er doped GaSb single crystals have been studied by scanning tunneling spectroscopy (STS) and cathodoluminescence (CL) in a combined scanning electron microscope-scanning tunnelling microscope system. The surface band gap in doped samples has bee[...]texto impreso
Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Golubev, VG. ; Kurdyukov, D.A. ; Pevtsov, A. B. ; Zamoryanskaya, M. V. | Amer Inst Physics | 2002-11-13Scanning tunneling microscopy and scanning tunneling spectroscopy (STS) are used to investigate the local electronic behavior of Pt-Si nanostructures fabricated in an opal matrix formed by silica spheres of 250 nm diameter. Si and Pt are regular[...]texto impreso
Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plugaru, R | IOP publishing ltd | 2001-09Scanning tunnelling microscopy (STM) has been sometimes applied in recent years to characterize porous silicon. In contrast, other forms of light emitting Si, such as nanocrystalline silicon films, prepared by different methods, have not been, o[...]texto impreso
Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Sekiguchi, T. | IOP publishing ltd | 2001-07Bulk ZnO single crystals grown by the hydrothermal and flux methods have been characterized by scanning tunnelling spectroscopy performed in the different crystalline faces. Normalized differential conductance has been found to depend on the fac[...]texto impreso
Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Ortega Villafuerte, Yanicet | IOP publishing ltd | 2011-08Al-doped ZnO nanorod networks and other microstructures have been grown by a thermal evaporation–deposition method with a mixture of ZnS and Al_2O_3 powders as precursor. Some of the grown structures consist of star-like arrays of nanorods arran[...]texto impreso
Ortega Villafuerte, Yanicet ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Elsever Science | 2009-03-15Sintering of a ZnS-SnO(2) mixture under argon flow leads to the growth of columnar nanoplate arrays as well as arrays of nanowires, nanorods and nanoplates with six-fold symmetry. The six-fold nanoplate structures correspond to a more advanced s[...]texto impreso
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Chioncel, M. ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier | American Institute of Physics | 2008-12-15?-Fe_2O_3 (hematite) nanostructures with various morphologies have been grown by thermal oxidation of compacted iron powder at temperatures between 700 and 900 degrees C. Different thermal treatments have been found to induce the growth of singl[...]texto impreso
Alonso Orts, Manuel ; Sanchez, Ana M ; Hindmarsh, Steven A ; López, Iñaki ; Nogales Díaz, Emilio ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Amer Chemical Soc | 2017-01-11Tailoring the shape of complex nanostructures requires control of the growth process. In this work, we report on the selective growth of nanostructured tin oxide on gallium oxide nanowires leading to the formation of SnO_2/Ga_2O_3 complex nanost[...]texto impreso
MgO crystals have been studied by scanning?electron acoustic microscopy under different experimental conditions. Contrast mechanisms in imaging are discussed and compared. The experimental results obtained by earthing or nonearthing the specimen[...]texto impreso
Piqueras de Noriega, Javier ; Ortega Villafuerte, Yanicet ; Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma | World Scientific Publ Co Pte Ltd | 2007Sintering of ZnO-SnO_2 and ZnO-MgO mixtures, with few at. % of Sn or Mg at 1280 C under argon flaw leads to the growth of microrods on the sample surface, which are formed by oriented stacks of nanoplates. Energy dispersive spectroscopy and cath[...]texto impreso
Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2008-11-12Sn doped GeO_2 nanowires and microwires have been grown by an evaporation-deposition method, using a mixture of Ge and SnO_2 powders as precursors. Comparison with undoped GeO_2 nanowires grown by the same method shows that the presence of Sn pr[...]