Información del autor
Autor Maestre Varea, David |
Documentos disponibles escritos por este autor (58)
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Fernández Sánchez, Paloma ; López Orozco, José Antonio ; Maestre Varea, David ; Hidalgo Alcalde, Pedro ; Besada Portas, Eva ; Sotillo Buzarra, Belén ; Neira Gómez, Andrea Paulette ; Pereyra Ocampo, Laura Victoria ; de las Heras de la Campa, Pablo | 2016-04El juego como modo de aprendizaje es algo inherente no sólo al ser humano sino, en general, al reino animal. Para cualquier mamífero el juego constituye la forma de aprendizaje fundamental. A través del juego se aprende a luchar, a defenderse y [...]texto impreso
Cathodoluminescence (CL) and remote electron beam induced current (REBIC) in the scanning electron microscope (SEM) has been used to investigate the electron recombination mechanisms in tin oxide. Sintered material prepared from high purity powd[...]texto impreso
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | American Institute of Physics | 2004-03Cathodoluminescence (CL) in the scanning electron microscope (SEM) has been used to investigate the luminescence mechanisms in tin oxide. Sintered material prepared from high purity powder has been found to show a strong dependence of the CL emi[...]texto impreso
Cathodoluminescence study of semiconductor oxide micro- and nanostructures grown by vapor deposition
Piqueras de Noriega, Javier ; Maestre Varea, David ; Ortega Mallén, Yolanda ; Cremades Rodríguez, Ana Isabel ; Fernández Sánchez, Paloma | Wiley-Blackwell | 2008-07starting SnO_2, powder. In-rich nanoislands were found to grow on some edges of the tubes. ZnO nanostructures doped with Sri or Eu were grown by adding SnO_2 and Eu(2)O(3) powder, respectively, to the ZnO precursor powder. All the samples have b[...]texto impreso
Rezgui, B. Drid ; Gourbilleau, F. ; Maestre Varea, David ; Palais, O. ; Sibai, A. ; Lemiti, M. ; Bremond, G. | American Institute of Physics | 2012-07-15Experimental investigation of photoconductivity in Si-rich silicon oxide (SRSO)/SiO_2 multilayer (ML) structures prepared by magnetron reactive sputtering is reported. Photocurrent (PC) measurements show that the PC threshold increases with decr[...]texto impreso
Guzmán Navarro, G ; Herrera Zaldivar, M. ; Valenzuela Benavides, J. ; Maestre Varea, David | American Institute of Physics | 2011-07-01We report a cathodoluminescence (CL) study of ß-Ga_2O_3 nanowires grown by thermal evaporation of GaN on Si(100) and Au/Si(00) substrates. Condensation and subsequent oxidation of metallic Ga is suggested as the growth mechanism of ß-Ga_2O_3 nan[...]texto impreso
Prado, Félix del ; Andersen, Hanne Flaten ; Taeño González, María ; Mhlen, Jan Petter ; Ramírez Castellanos, Julio ; Maestre Varea, David ; Karazhanov, Smagul ; Cremades Rodríguez, Ana Isabel | Nature Publishing Group | 2020-03-26Transition metal oxides potentially present higher specific capacities than the current anodes based on carbon, providing an increasing energy density as compared to commercial Li-ion batteries. However, many parameters could influence the perfo[...]texto impreso
Maestre Varea, David ; Haeussler, D. ; Cremades Rodríguez, Ana Isabel ; Jaeger, W. ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2011-09-22Sn-doped In2O3 arrow-shaped nanorods have been grown by a catalyst-free evaporation deposition method. Transmission electron microscopy (TEM) investigations reveal a complex defect structure consisting of nanoprecipitates, dislocation loops, and[...]texto impreso
Bartolomé Vílchez, Javier ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Amatti, M. ; Piqueras de Noriega, Javier | Pergamon-Elsevier Science Ltd | 2013-04Microrods and hierarchical structures of indium-zinc-oxide (IZO) with different compositions were grown by thermal treatments of mixtures of InN and ZnO powders. In long rods, an increase in Zn content along the growth axis is revealed by energy[...]texto impreso
Cristian Vasquez, G. ; Andrea Peche-Herrero, M. ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Ramirez-Castellanos, Julio ; Gonzalez-Calbet, José M. ; Piqueras de Noriega, Javier | RSC Royal Society of Chemistry | 2013Cr doped TiO_2 rutile nanoparticles have been used as precursor of microrods and microtubes grown by a vapor-solid method. The grown microstructures have nearly square cross-sections of a few microns wide and lengths of up to about 100 microns. [...]texto impreso
En la presente tesis doctoral se exponen y discuten los principales resultados extraídos de la investigación realizada sobre muestras de SnO2 y TiO2 sinterizado, o en forma de micro- y nanoestructuras alargadas. Ambos materiales se encuentran en[...]texto impreso
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | IOP publishing ltd | 2004-11Remote electron beam induced current (REBIC) and cathodoluminescence (CL) modes in the scanning electron microscope (SEM) have been used to investigate SnO2 sintered samples. The study of the electrically active boundaries present in the oxide s[...]texto impreso
Prado Hurtado, Félix del ; Taeño González, María ; Maestre Varea, David ; Ramírez Castellanos, Julio ; González Calbet, José María ; Cremades Rodríguez, Ana Isabel | Pergamon Elsevier Science | 2019-06Graphene oxide (GO) based composites functionalized with nanoparticles are emerging as potential candidates for multifunctional devices. As the synthesis route can strongly influence the way in which the nanoparticles are anchored to GO and the [...]texto impreso
Maestre Varea, David ; Plugaru, R ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Materials Research Society | 2003The luminescence of titanium oxide and tin oxide has been investigated by cathodoluminescence in the SEM, as a function of the structural changes induced by thermal treatments. The evolution of the luminescence of TiO2 rutile, anatase and mixtur[...]texto impreso
Rezgui, B. ; Sibai, A. ; Nychyporuk, T. ; Lemiti, M. ; Bremond, G. ; Maestre Varea, David ; Palais, O. | Amer Inst Physics | 2010-05-03The size of silicon quantum dots (Si QDs) embedded in silicon nitride (SiN(x)) has been controlled by varying the total pressure in the plasma-enhanced chemical vapor deposition (PECVD) reactor. This is evidenced by transmission electron microsc[...]texto impreso
Cristian Vasquez, G. ; Andrea Peche-Herrero, M. ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Ramirez-Castellanos, Julio ; María Gonzalez-Calbe, José ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2013-01-31Rutile TiO_2 nanoparticles doped with V, Cr, or Mn ions have been synthesized via a modified Pechini method using polymeric precursors. The final particle sizes range between 20 and 500 nm depending on the selected dopant. The TiO_2 rutile phase[...]texto impreso
Moldarev, D. ; Taeño González, María ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Karazhanov, Smagul Zh ; Marstein, E. | Elsevier | 2020-05-08Due to the combination of low cost materials deposition and device fabrication methods as well as competitive efficiency compared to the other Si solar cell architectures, the hybrid organic-silicon solar cells have attracted attention of the sc[...]texto impreso
Taeño González, María ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel | Elsevier | 2020-06-25Complex patterning of surfaces commonly requires a significant effort in terms of time, cost, and advanced post-fabrication treatments design, which could be overcome by self-organization mechanisms avoiding damage to the surface materials and e[...]texto impreso
Solano, Ricardo A. ; Herrera, Adriana P. ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel | Hindawi Ltd | 2019Anatase TiO_2 nanoparticles doped with iron ions have been synthesized via the green chemistry method using aqueous extract of lemongrass (Cymbopogon citratus) obtained from Soxhlet extraction and doped by wet impregnation. The TiO_2 anatase pha[...]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
In this work we report on the growth of Fe_(1-x)Gax films by means of the electrodeposition technique in baths containing sodium citrate as an antioxidant agent. We have investigated the effect of the electrolyte composition in terms of its Ga c[...]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
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
Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | American Institute of Physics | 2005-02-15Sintering SnO_2 under argon flow at temperatures in the range of 1350-1500 degreesC causes the formation of wires, rods, and tubes on the sample surface. At high temperatures of the mentioned range, microwires with lengths of hundreds of microns[...]