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2023 Descuentos MDPI, This study focuses on the fabrication of polymer nanocomposite films using polyvinyl alcohol (PVA)/graphene quantum dots (GQDs). We investigate the relationship between the structural, thermal, and nanoscale morphological properties of these films and their photoluminescent response. Although according to X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and differential thermal analysis (DTA), the incorporation of GQDs does not significantly affect the percentage crystallinity of the PVA matrix, for a range of added GQD concentrations, atomic force microscopy (AFM) showed the formation of islands with apparent crystalline morphology on the surface of the PVA/GQD films. This observation suggests that GQDs presumably act as nucleating agents for island growth. The incorporation of GQDs also led to the formation of characteristic surface pores with increased stiffness and frictional contrast, as indicated by ultrasonic force microscopy (UFM) and frictional force microscopy (FFM) data. The photoluminescence (PL) spectra of the films were found to depend both on the amount of GQDs incorporated and on the film morphology. For GQD loads >1.2%wt, a GQD-related band was observed at similar to 1650 cm(-1) in FT-IR, along with an increase in the PL band at lower energy. For a load of similar to 2%wt GQDs, the surface morphology was characterized by extended cluster aggregates with lower stiffness and friction than the surrounding matrix, and the PL signal decreased., Universidad de Castilla La Mancha, Fondo Europeo de Desarrollo Regional (Unión Europea), Ministerio de Ciencia e Innovación (España), Unión Europea, Comunidad de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2023 by the authors. Licensee MDPI, This work was supported by MICINN projects (RTI2018-097195-B-I00, PIE 2021-60-E-030, PIE 2010-6-OE-013 and PID2021-122562NB-I00). B.R. acknowledges financial support from MICINN (contract No. PRE2019-088162)., Polymorphous WO_(3) micro- and nanostructures have been synthesized by the controlled Joule heating of tungsten wires under ambient conditions in a few seconds. The growth on the wire surface is assisted by the electromigration process and it is further enhanced by the application of an external electric field through a pair of biased parallel copper plates. In this case, a high amount of WO_(3) material is also deposited on the copper electrodes, consisting of a few cm^(2) area. The temperature measurements of the W wire agrees with the values calculated by a finite element model, which has allowed us to establish the threshold density current to trigger the WO_(3) growth. The structural characterization of the produced microstructures accounts for the gamma-WO_(3) (monoclinic I), which is the common stable phase at room temperature, along with low temperature phases, known as delta-WO_(3) (triclinic) on structures formed on the wire surface and e-WO_(3) (monoclinic II) on material deposited on external electrodes. These phases allow for a high oxygen vacancies concentration, which is interesting in photocatalysis and sensing applications. The results could help to design experiments to produce oxide nanomaterials from other metal wires by this resistive heating method with scaling-up potential., Ministerio de Ciencia e Innovación (MICINN) / FEDER, Ministerio de Ciencia e Innovación (MICINN) / FSE, Ministerio de Ciencia e Innovación (MICINN), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

El texto completo de este trabajo no se encuentra disponible por no haber sido facilitado aún por su autor, por restricciones de copyright, o por no existir una versión digital, Novel transparent semiconducting oxides have emerged as key materials for a variety of optoelectronic applications due to their ultra-wide band gap. Owing to the critical role of native defects and impurities in the optoelectronical properties, investigation in detail of the electronic structure of these oxides has become a challenge, being luminescence technique a powerful way to gain insight into the electronic levels. Here, the photoluminescence temperature dependence of Li doped Zn2GeO4 microrods is analysed and discussed in the framework of the electronic levels structure related to native defects and Li impurities. Unlike the undoped material, the blue emission (2.8 eV) of Li-doped germanate exhibits a negative thermal quenching as its photoluminescence intensity increases with increasing temperature. The mechanisms underlying this anomalous behaviour are discussed with the aid of X-ray photoemission spectroscopy and first principles calculations. This study has helped us to understand the role of Li in the electronic structure and optical response of Zn2GeO4. Our results highlight the versatility of Zn2GeO4 luminescence through Li doping, which could be exploited in optoelectronic devices with bespoke properties., Ministerio de Ciencia e Innovación (España), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

El principal objetivo de la propuesta es promover nuevas vías de formación de doctorandos en aspectos para los cuales rara vez se incide en los diversos Programas de Doctorado. Los resultados esperados son (i) Mejora de la metodología de formación de doctorandos por parte de los profesores del Programa de Doctorado en Física, bajo el auspicio de la Comisión Académica del Programa, con énfasis en la difusión de sus resultados científicos. (ii) Establecimiento de las bases para organizar actividades formativas transversales similares y de interés para otros Programas de Doctorado del área de Ciencias Experimentales, bajo los auspicios de la Escuela de Doctorado de la Universidad Complutense.

© 2008 Elsevier B.V. This work was partially supported by the following Projects: ESP2006-09935, Spanish ‘‘Ministerio de Educación y Ciencia’’; S-0505/MAT-0279, Spanish ‘‘Comunidad de Madrid’’; FP7-SEC- 2007-01, European Commission, and Contract number 14240/00/ NL/SH, European Space Agency. One of the authors VC is thankful to the Ministry of Education and Science, Spain for the financial support. The author NV is grateful to Department of Science and Technology, Govt. of India for providing the BOYSCAST fellowship. The author JRF is thankful to the Universidad Autónoma of Madrid for financial support., The II-VI compound semiconductor crystal cadmium zinc telluride (CZT) is very important in the field of room-temperature radiation detectors and medical imaging applications. In the present study, bulk CZT single crystal has been grown by (i) oscillatory Bridgman technique, (ii) from vapour phase using pyrolytic boron nitride ampoule in the Bridgman geometry, and (iii) by using a Pt tube used for the ampoule support as a cold finger. Several improvements were found in the thermal environments such as the effects of superheating and reduced growth velocity, as well as improvements in the grain size and zinc composition along the ingot. The compositional homogeneity and its current-voltage characteristic behaviour have been analysed using energy dispersive X-ray analysis and I-V method, respectively., España. Ministerio de Educación y Ciencia, Comunidad de Madrid, European Commission, European Space Agency, Department of Science and Technology, Govt. of India, Universidad Autónoma de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2007 IOP Publishing Ltd. This work has been supported by the Ministry of Education and Science of Spain under a Ramon y Cajal Contract, by the project MAT2003-09873 and by the project MEC (MAT 2003-00455)., The luminescence of porous InP prepared by electrochemical etching is investigated by cathodoluminescence (CL) in a scanning electron microscope (SEM). Anodization causes a strong reduction of CL intensity as well as a blue spectral shift. Additional blue shift and enhancement of CL intensity is observed in samples cracked in vacuum by the effect of the SEM electron beam, which is explained by the reduction of the influence of surface states on the recombination mechanism. The relationship of the CL spatial distribution with the multilayer porous structure is described., España. Ministerio de Educación y Ciencia, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2009 American Institute of Physics. This work was partially supported by the following Projects: Grant Nos. MEC-ESP2006-09935, CM-S-0505/ MAT-079, and FP7-SEC-2007-01 “European Commision,” and Contract No. 14240/00/NL7SH “European Space Agency.” One of the authors, V.C., thanks MEC, Spain for financial support. N.V. is grateful to Department of Science and Technology, Government of India for providing the BOYSCAST fellowship. The author J.R.F. is thankful to the Universidad Autónoma of Madrid for the financial support., Cadmium 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), and current-voltage behavior at room temperature. The results shows that Cd and Te vacancy concentration depend on the indium and zinc concentrations. CL measurements indicate a relationship between radiative centers associated to Cd and Te vacancies and resistivity values., European Commision, European Space Agency, Department of Science and Technology, Government of India, Universidad Autónoma de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2001 Elsevier Science B.V. This work was supported by DGES (Project PB96- 0639)., We report here the studies carried out in zinc diffused n-type GaSb by cathodoluminescence (CL) microscopy and by scanning tunneling spectroscopy. Samples with different diffusion profiles measured by secondary ion mass spectrometry (SIMS) were obtained. CL plan-view observations show high homogeneity in the diffused layers. Cross-sectional measurements of the Zn diffused layers were performed by current imaging tunneling spectroscopy (CITS). The junction border was revealed clearly in the CITS images and conductance spectra recorded at differents points of the layers provided information on the local surface band gaps and the conductive behaviour. The results were related to the diffusion profiles and were found to agree with diffusion models suggested previously., DGES, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2009 IOP Publishing Ltd. This work was supported by MEC (Project MAT2006-01259)., Bi doped ZnO nanowires and rods have been grown by a catalyst free evaporation-deposition method with precursors containing either ZnO and Bi_2O_3 or ZnS and Bi_2O_3 powders. The use of ZnS as a precursor was found to lead to a higher density of nano- and microstructures at lower temperatures than by using ZnO. Energy dispersive x-ray spectroscopy (EDS) shows that the Bi content in the wires and rods is in the range 0.15-0.35 at%. Bi incorporation was found to induce a red shift of the near band gap luminescence but no quantitative correlation between the shift and the amount of Bi, as measured by EDS, was observed. The I-V curves of single Bi doped wires had linear behaviour at low current and non-linear behaviour for high currents, qualitatively similar to that of undoped wires., MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2007 IOP Publishing Ltd. International Conference on Nanoscience and Technology (2006.Basel, Switzerland ). This work has been supported by the Ministry of Education and Science of Spain under a Ramon y Cajal Contract, by the project MAT2003-09873 and by the project MEC (MAT 2003-00455), The scope of this paper is to analyse the effect of Au and Cr impurities, diffused onto GaSb substrates on the formation of nanodots created by LEIS using Ar+ ions It is concluded that oblique incidence in rotating configuration delays the formation of the nanodots compared to previously reported normal incidence experiments. The presence of cracks induced by the sputtering process has been observed both in the Au and Cr diffused samples. Cathodoluminescence (CL) spectra obtained in irradiated samples both pure and Cr-diffused have revealed no difference between them, showing the usual three band encountered in this material (Band Gap at 798 meV, A Band at 777 meV and tail-states at 815 meV). However, a fourth band has been detected in the Au sample centered at 769 meV., Ministry of Education and Science of Spain, MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2002 Elsevier Science B.V. International Conference on Defects: Recognition, Imaging and Physics in Semiconductors (9. 2001. Ramini, Italia), The defect structure of Te-doped GaSb samples co-doped with Er_2O_3 and grown by the vertical Bridgman technique has been analysed. This study was carried out for different Er and Te concentrations. The defect structure of the samples has been analysed by means of cathodoluminescence (CL), scanning electron microscopy (SEM) and wavelength dispersive X-ray microanalysis (WDX). The effect of the defect structure and sample composition on the electrical properties of the material has been established taking into account the results obtained by means of the van der Pauw technique., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2005 Elsevier B.V. All rights reserved. This work was supported by the EU (HPRN-CT-2001-00199) and MECD (MAT2003-00455)., b-doped GaSb ingots have been grown by the Bridgman method. The defect structure and compositional homogeneity of the crystals have been investigated by cathodoluminescence and X-ray microanalysis in the scanning electron microscope. The nature of the point defects has been found to depend on the position along the growth axis. Doping with Yb has been found to reduce the luminescence intensity of GaSb and no infrared emission related to intra-ionic transitions of the Yb_(3+) ions has been detected, EU, MECD, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© The Minerals, Metals & Materials Society and ASM International 2010. Financial support from CICYT (Project Nos. MAT2003-01172 and MAT2006-11202) is gratefully acknowledged. Two of the authors, PH and CMC, thank CSIC for an I3P fellowship and an I3P contract, respectively. We also thank A. García-Delgado for assistance with electron microscopy and C.C. Moreno-Hernández and J.A. Jiménez- Rodríguez for assistance with X-ray diffraction. Finally, the authors make a special mention in memory of P.J. González-Aparicio for his assistance with electron microscopy during all these years., The 7075 alloy is an Al-Zn-Mg-Cu wrought age-hardenable aluminum alloy widely used in the aeronautical industry. The alloy was accumulative roll bonded at 300 A degrees C (573 K), 350 A degrees C (623 K), and 400 A degrees C (673 K), and the microstructure, texture, and hardness were investigated. Cell/(sub)grain size in the nanostructured range, typical beta-fiber rolling texture, and homogeneous hardness through thickness were determined in all cases. Misorientation was different at each processing temperature. At 400 A degrees C, the presence of elements in solid solution and the partial dissolution of the hardening precipitates lead to a poorly misoriented microstructure with a high dislocation density and a homogeneous beta-fiber texture of low intensity, typical of intermediate degrees of rolling. At 350 A degrees C and 300 A degrees C, highly misoriented microstructures with smaller dislocation density and intense heterogeneous beta-fiber rolling texture are observed, especially at 350 A degrees C, wherein the degree of dynamic recovery (DRV) is higher. Hardness of the accumulative roll bonded samples is smaller than that of the starting material due to particle coarsening, and it is affected by solid solution and/or by fine precipitates produced by reprecipitation of the elements in solid solution., CICYT, CSIC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

(c) Sociedad Española de Cerámica y Vidrio, Consejo Superior de Investigaciones Científicas. Licencia Creative Commons 3.0 España (by-nc). Este trabajo ha sido subvencionado por CICYT a través del proyecto ESP-98 1340., En 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 efectivo de ambos dopantes a lo largo de la dirección de crecimiento del material. Mediante medidas de efecto Hall se ha determinado el tipo de portadores mayoritarios (huecos) así como los valores de la movilidad, la densidad de portadores y la resistividad para cada una de las concentraciones. Los análisis de dispersión de energías de rayos X (EDAX) y de microscopio electrónico de barrido (SEM) han demostrado la presencia de agregados formados por los iones de tierras raras y Sb para las concentraciones de dopante más altas. La reducción de los defectos nativos tales como las vacantes de Ga y Ga en posición de Sb por los iones de Er ha sido también demostrado a través de análisis de catodoluminiscencia., In this work the study of GaSb crystals grown by the Bridgman method doped with Er and Nd with different concentrations has been carried out. Atomic absorption analysis have been developed for obtaining the effective segregation coefficient of the two dopants along the growth direction of the material. The resistivity, mobility and density of carriers were obtained by the van der Pauw technique fur the different dopant concentrations. The Energy dispersive X ray analysis (EDX) and the scanning electron microscope (SEM) have demonstrated the presence of precipitates made from Sb and rare earth elements for the highest dopant concentrations. Cathodoluminescence (CL) analysis have proved that the rare earth elements have a reduction effect of native defects in GaSb., CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. This work has been supported by MICINN (Projects MAT 2009-07882 and Consolider Ingenio CSD 2009-00013) and by BSCH-UCM (Project GR35-10A-910146). The authors are grateful to Dr Luca Gregoratti at the Sincrotrone Trieste for useful advises on XPS measurements., The 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 for Sn doped nanowires. X-ray photoelectron spectroscopy measurements have been performed to calculate the work function of Sn doped Ga2O3. The results show improved field emission properties of Sn doped Ga2O3 nanowires, with a lower threshold field (below 1.0 V/mu m). The obtained values are competitive with those achieved in other nanostructured materials, including carbon nanotubes., MICINN, BSCH-UCM, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2010 Elsevier Inc. The authors gratefully acknowledge the financial support of the Spanish project MAT2006 01251 Thanks are also due to Dr M T Perez Prado for helpful discussion, The mechanical properties of particle-reinforced aluminum matrix composites (AMCs) are largely dependent on the microstructure of the materials, which in turn is largely dependent on the processing history [1]. Powder metallurgy (PM) is a commonly used processing technique for producing AMCs since it can reduce reinforcement segregation, typical of casting metallurgy processes [2]. When there is a large size difference between reinforcing and aluminum particles, high energy ball milling (BM) is used to manufacture AMCs successfully [3,4]. In the BM process, the aluminum particles are fragmented and re-welded continuously, during which the brittle reinforcing particles are fragmented and become embedded in the softer aluminum matter. EBSD has been used extensively to characterise submicrometer microstructure in monolithic deformed alloys [5,6]. However, to the authors' knowledge, EBSD has scarcely been used to investigate AMCs and there is limited information on the matrix microstructure of milled AMCs after consolidation processes such as extrusion [7–9]. In the present work, electron back-scattered diffraction (EBSD) has been used to characterise matrix grain size and grain orientation in six powder metallurgy AA6061/MoSi2/15p composites and three unreinforced matrices processed with and without ball milling, followed by hot extrusion. The aim is to know the effect of milling on the matrix grain structure of extruded AMCs, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© Springer Science+Business Media, LLC 2008. This work was supported by Projects CAM (S-0505/MAT/0279) and MEC (project MAT 2006/1259)., Bi doped and Bi and Yb codoped CdTe crystals grown by the Bridgman method have been characterized by cathodoluminescence (CL) in the scanning electron microscope. CL images show a dense network of highly decorated grain boundaries in the Bi doped samples and dopant striations in the codoped crystals, attributed to the presence of Yb. Bi contributes to the appearance of the A luminescence band at 1.43 eV. The influence of Yb dopant on the CL spectra is discussed., CAM, MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2010 Elsevier B.V. All rights reserved. Financial support from CICYT (Project MAT2009-14452) is gratefully acknowledged. C.M. Cepeda-Jimenez thanks the Spanish National Research Council (CSIC) for a I3P contract. We also thank F.F. Gonzalez-Rodriguez for assistance during hot torsion. Finally, an especial mention in memory of P.J. Gonzalez-Aparicio for his help and assistance with electron microscopy during all these years is made., Hot torsion tests to fracture to simulate thermomechanical processing were carried out on a solution-treated Al-Cu-Mg alloy (Al 2024-T351) at constant temperature. Torsion tests were conducted in the range 278-467 degrees C, and at two strain rates, 2.1 and 4.5 s(-1). Electron backscatter diffraction (EBSD) was employed to characterize the microtexture and microstructure before and after testing. The microstructural evolution during torsion deformation at different temperatures and strain rate conditions determines the mechanical properties at room temperature of the Al 2024 alloy since grain refining, dynamic precipitation and precipitate coalescence occur during the torsion test. These mechanical properties were measured by Vickers microhardness tests. At 408 degrees C and 2.1 s(-1) the optimum combination of solid solution and incipient precipitation gives rise to maximum ductility and large fraction of fine and misoriented grains (f(HAB) = 54%). In contrast, the increase in test temperature to 467 degrees C produces a sharp decrease in ductility, attributed to the high proportion of alloying elements in solid solution. Both the stress-strain flow curves obtained by torsion tests and the final microstructures are a consequence of recovery phenomena and the dynamic nature of the precipitation process taking place during deformation., CICYT, Spanish National Research Council (CSIC), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2005 WILEY-VCH Verlag GmbH. International Conference on Extended Defects in Semiconductors (10. 2004. Chernogolovka, Rusia), This paper presents cathodoluminescence, electrical and structural characteristics of (11-20)-oriented 4H-SiC substrates, aiming at determining properties of some extended defects. As-grown basal plane dislocations with the Burgers vector b = 1/3 < 11-20 > previously revealed to be associated to a radiative recombination level at 1.80 eV. Well controlled dislocations were here introduced by annealing the sample under compressive stress at 973 K. After the annealing, double stacking faults were detected, formed by two Shockley partial dislocations gliding in two successive basal planes. These defects proved to introduce a rectifying behaviour during forward voltage operation, with a corresponding barrier height value of 0.58 eV at room temperature. Cathodoluminescence measurements allowed to attribute a radiative level at 1.80 eV to the extended defects, giving rise to a double luminescence peak., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1998 Elsevier Science Ltd. All rights reserved. Acknowledgements—GrowtThis work was supported by DGES (PB96-0639) and by CICYT (ESP95-0148 and 95-0086-OP)., The effect of aluminium on the defect structure of GaSb crystals, grown by the vertical Bridgman technique, has been investigated by cathodoluminescence (CL) in the scanning electron microscope. Crystals have been found to be highly homogeneous along the growth axis with the exception of the top end which showed Al accumulation. The CL results show decoration of extended defects by Al but contrary to the case of other dopants Al has not been found to cause a significative reduction of native accepters. A CL band at about 850 meV appears to be related to the presence of aluminium., DGES, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1999 IOP Publishing Ltd. This work has been supported by the DGES (project No PB96-0639) and CICYT (projects ESP95-0148 and ESP98-1340)., The luminescence properties of In doped GaSb single crystals have been studied by the cathodoluminescence (CL) technique in the scanning electron microscope. It has been found that indium induces a certain reduction on the native acceptor concentration in contrast to what occurs with other isoelectronic dopants (e.g. aluminium). Large In concentrations lead to the formation of the ternary compound In_xGa_(1-x)Sb as revealed by CL spectra and x-ray measurements. In particular, a luminescence band and x-ray diffraction peaks observed in highly doped samples are attributed to the presence of In_xGa_(1-x)Sb., DGES, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© The American Physical Society. This Work Was Supported By The DGICYT (Project No. PB93-1256) And CICYT (Project No. 95-0086-OP)., The luminescence properties of transition-metal (Cr, V, and Ru)-doped GaSb single crystals have been studied by a cathodoluminescence (CL) technique in a scanning electron microscope. Spatial segregation of impurities along the longitudinal direction of the crystals grown by the Bridgman method has been investigated. These dopants suppress the native acceptor concentration to varying extent. The behavior of Ru has been found to be different from the behavior of V and Cr. In particular the complete disappearance of the 777 meV (band A) emission has been observed in GaSb:Ru with a low doping level. A peak at 767 meV is also seen in this sample which, to the best of our knowledge, has not been previously observed in GaSb. The CL results have been complemented by x-ray-microanalysis measurements to ascertain the effect of doping level on the luminescence properties., DGICYT, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2008 IOP Publishing Ltd. This work was supported by MEC (Project MAT2006-01259)., Sn 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 prevents the formation of sharp bends, which makes the wires more suitable for waveguiding applications. Incorporation of about 0.5 at.% of Sn into the wires influences their morphology and gives rise to wires showing two different cross-sectional dimensions along the growth axis. Sn does not influence the luminescence spectra in the visible range but causes the appearance of emission bands in the near-infrared range. The waveguiding behavior of the Sn doped wires for green and red laser light has been demonstrated., MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2014 AIP Publishing LLC. This work has been supported by MINECO (Project Nos. MAT 2012-31959 and CSD 2009-00013). J.B. acknowledges the financial support from Universidad Complutense de Madrid., Electric field induced mechanical resonances of In2O3 microrods are studied by in-situ measurements in the chamber of a scanning electron microscope. Young's moduli of rods with different cross-sectional shapes are calculated from the resonance frequency, and a range of values between 131 and 152GPa are obtained. A quality factor of 1180-3780 is measured from the amplitude-frequency curves, revealing the suitability of In2O3 microrods as micromechanical resonators. The Young's modulus, E, of one of the rods is also measured from the elastic response in the force-displacement curve recorded in an atomic force microscope. E values obtained by in-situ scanning electron microscopy and by atomic force microscopy are found to differ in about 8%. The results provide data on Young's modulus of In2O3 and confirm the suitability of in-situ scanning electron microscopy mechanical resonance measurements to investigate the elastic behavior of semiconductor microrods., MINECO, Universidad Complutense de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2009 Elsevier B.V. All rights reserved. Financial support from CICYT (Project MAT2003-01172 and MAT2006-11202) is gratefully acknowledged. C.M. Cepeda- Jimenez thanks the Spanish National Research Council (CSIC) for a I3P contract. We also thank F.F. Gonzalez-Rodriguez for assistance during hot rolling. Finally, an especial mention in memory of P.J. Gonzalez-Aparicio for his help and assistance with electron microscopy during all these years is made., The microstructure and mechanical properties in the interface region of a multilayer composite laminate based on Al-Zn (Al 7075) and Al-Cu (Al 2024) alloys have been mainly characterized by EBSD and shear tests. It is shown that varying solution heat treatments affect the microstructure of the constituent aluminium alloys in the bonding region and, as a consequence, the interfacial mechanical properties. The increase in the solution treatment time improves the interfacial toughness of the multilayer aluminium laminate due to higher intrinsic toughness of the constituent aluminium alloys., CICYT, Spanish National Research Council (CSIC), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2009 American Chemical Society. This work has been supported by MEC (Project MAT 2006-01259). The authors are grateful to Dr. Luca Gregoratti at the Sincrotron Trieste for useful advises on XPS measurements., GeO_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, which make them more appropriate for waveguiding purposes. Cathodoluminescence (CL.) in the scanning electron microscope (SEM) has been used to investigate the complex light emission from the nanowires. Rare earth ion emission lines and defect related bands have been observed in Eu- and Er-doped nanowires. Optical coupling and waveguiding behavior of Er-doped GeO_2 nanowires have been demonstrated for green laser light and for Er excited luminescence in the wires. In Mn-doped GeO_2 nanowires a band centered at 1.75 eV had been detected. X-ray photoemission measurements show the presence of GeO oxide in the surface of the GeO_2 wires, which influences their native defect structure., MEC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2002 IOP Publishing Ltd. This work was supported by MCYT (Project MAT2000-2119). Conference on Extended Defects in Semiconductors (EDS 2002)(2002. Bologna, Italia), The luminescence of Te-doped GaSb crystals codoped with Er2O3 has been studied by means of cathodoluminescene (CL) using a scanning electron microscope. Doping with erbium oxide causes a substantial increase of the luminescence intensity of the crystals and spectral broadening. Deconvolution of the CL spectra reveals the existence of four components. The presence of erbium oxide induces a decrease of the 746 meV emission characteristic of Te-doped samples. CL images show a complex distribution of recombination centres which depends to a large extent on he local Te concentration., MCYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007. This work was supported by MEC (project MAT 2003-00455) and by UCM-CM (Group 910146)., The defect structure of sintered SnO_2 was investigated by high-resolution transmission electron microscopy (HRTEM), cathodoluminescence (CL), and electrical measurements. HRTEM shows the presence of the SnO phase in the sintered samples as well as twinning, stacking faults, and disordered intergrowths. The sintered samples annealed under an oxygen atmosphere show changes in the defect structure and in the CL spectra. In particular, the intensity of a CL band at 1.94 eV, related to oxygen vacancies, decreased as the electrical resistivity increased. The results are discussed by considering the presence of stoichiometric defects such as oxygen vacancies and Sn interstitials in the final structure and their evolution during the annealing process under an oxygen atmosphere., MEC, UCM-CM, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© The Minerals, Metals & Materials Society and ASM International 2010. Financial support from CICYT (Project Nos. MAT2003-01172 and MAT2006-11202) is gratefully acknowledged. Two of the authors, PH and CMC, thank CSIC for an I3P fellowship and an I3P contract, respectively. We also thank A. García-Delgado for assistance with electron microscopy and C.C. Moreno-Hernández and J.A. Jiménez- Rodríguez for assistance with X-ray diffraction. Finally, the authors make a special mention in memory of P.J. González-Aparicio for his assistance with electron microscopy during all these years., Two aluminum multilayer laminates have been processed by hot roll bonding following similar processing paths. The first one is constituted by alternated Al 2024 and Al 1050 layers (ALH19) and the second one by alternated Al 7075 and Al 1050 layers (ADH19). The influence of the constituent materials in the multilayer laminates both during the processing at high temperature and during the subsequent mechanical characterization has been analyzed. The mechanical behavior of the as-received materials at the processing conditions has been characterized by hot torsion. Multilayer laminates have been tested at room temperature under impact Charpy tests, three-point bend tests, and shear tests on the interfaces. The relative toughness increase compared to the constituent materials was much higher for the ADH19 laminate based on the high-strength Al 7075 alloy than for the ALH19 laminate. This is attributed to the different fracture mechanism., CICYT, CSIC, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

©1999 The American Physical Society. This work was supported by DGES (PB96-0639) and by CICYT (ESP98-1340) (MAT98-1306E)., V- 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 resolution. Precipitates in both kinds of doped samples show a nearly metallic behavior. The surface band gaps in the GaSb matrix have been found to depend on the dopant. [S0163-1829(99)06439-5]., DGES, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© The Royal Society of Chemistry 2010. This work was partially supported by the following projects: ESP2006-09935, Spanish ‘‘Ministerio de Educaci_on y Ciencia’’; S-0505/MAT-0279, Spanish ‘‘Comunidad de Madrid’’; FP7- SEC-2007-01, European Commission, and Contract number 14240/00/NL/SH, European Space Agency. V.C. is thankful to the Ministry of Education and Science, Spain for financial support. N.V. is grateful to Department of Science and Technology, Govt. of India for providing the BOYSCAST fellowship. J.R.F. is thankful to the Universidad Autónoma of Madrid for financial support., Bulk CZT crystals doped with Bi (1 x 10(19) at/cm(3)) have been grown by the Oscillatory Bridgman method, the growth velocity and the zinc concentration profile being improved by the insertion of a Pt tube acting as a cold finger. The stoichiometric uniformity was examined by energy dispersive X-ray analysis, and the zinc concentration was confirmed by inductively coupled plasma mass spectroscopy and cathodoluminescence measurements. The resistivity value was in the range of 8 x 10(8) Omega cm , being smaller for the passivated sample, which at the same time had counter device properties., Spanish "Ministerio de Educacion y Ciencia'', Spanish "Comunidad de Madrid'', European Commission, European Space Agency, Department of Science and Technology, Govt. of India, Universidad Autónoma de Madrid, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2007 Elsevier B.V. All rights reserved. International Conference on Crystal Growth (15. 2007 . Salt Lake City,Utah). This work has been partly supported by the projects CAM SENSORCDT S-0505/MAT/0209 and EU FP6 PHOLOGIC 017158., Cadmium 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 doped with Ge at the concentration of 5 x 10(17) cm(-3) and co-doped with the rare element Yb at the concentration range from 1 x 10(17) to 1 x 10(19) cm(-3). The CdTe:Ge:Yb samples were studied by the structural and electrical characterization techniques, low-temperature photoluminescence (PL) and cathodoluminescence (CL) spectroscopy and CL imaging. Experimental findings testify that homogeneous crystals and layers of reasonably good structural quality can be grown with the Yb concentration below the value of 5 x 10(18)cm(-3) that is estimated to be the limit for Yb solubility in CdTe:Ge:Yb. These findings seem to be related with the purification effect caused by the interaction of the Yb dopant with the group I residual impurities., CAM, EU, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1998 IOP Publishing Ltd. This work has been supported by DGES (PB96-0639) and by CICYT (ESP95-0148 and 95-0086-OP)., GaSb single crystals with different Er concentrations have been studied by cathodoluminescence in the scanning electron microscope. Low Er doping has been found to reduce the concentration of native accepters. In crystals with higher Er concentrations, Er-Sb precipitates form and doping becomes less efficient in suppressing the accepters. In these samples intraionic Er luminescence is observed., DGES, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1999 Elsevier Science B.V. Conference on Crystal Growth, held in Conjunction with the 10th International Conference on Vapor Growth and Epitaxy (ICCG-12/ICVGE-10) (12. 1998. Jerusalen). This work has been supported by CICYT (ESP95-0148 and 95-0086-OP) and DGES PB96- 0639 (CICYT, Spain)., The distribution of Er in bulk GaSb ingots grown by vertical Bridgman technique has been investigated for different concentrations. The resistivity, mobility and carrier density were analysed. The formation of Er-Sb compounds and the incorporation of Er at subgrain boundaries has been shown by cathodoluminescence studies., CICYT, Spain, DGES, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2000 Elsevier Science S.A. Symposium F: Process Induced Defects in Semiconductors (1999. Estrasburgo, Francia) This work has been supported by CICYT under the project ESP-98 1340., In 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 has revealed the formation of precipitates at the highest doping levels for both Er- and Nd-doped GaSb. Cathodoluminescence analysis shows the reduction of the defect band induced by the rare earth (RE) elements. For high dopant concentrations the precipitation phenomena reduce this effect. Thermal treatments have produced an enhancement of the p-type properties of the samples. For a dopant density of 2 x 10(19) cm(-3) this effect is more pronounced., CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2002 Published by Elsevier Science B.V. This work has been supported by CICYT under theproje ct ESP-98 1340 and by INTAS-ESA Project number 99 01814., Nd-doped GaSb bulk crystals with three different dopant concentrations have been grown by the vertical Bridgman technique. The axial segregation has been characterised by obtaining the effective segregation coefficient. Differences in the value of this coefficient show its dopant concentration dependence. Resistivity, carrier density and mobility have also been obtained showing the p-type nature of this material. Structural and compositional properties have been studied revealing some inclusions with high Nd concentration in the highest Nd-doped ingot., CICYT, INTAS-ESA, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2007 IOP Publishing Ltd. This work has been supported by MEC (Project MAT2003-00455) and UCM-CM (Group 910146)., High aspect ratio GeO_2 nano- and microwires have been grown by thermal treatment at 600 degrees C of compacted Ge powder under argon flow. The wires have cross-sectional dimensions from less than 100 nm to about 1 mu m, depending on the duration of the treatment, and lengths of up to about 2000 mu m. Waveguide behaviour of the wires was demonstrated for visible light, which shows the potential applications of these structures for optical nanodevices., MEC, UCM-CM, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© IEEE-Inst Electrical Electronics Engineers Inc. Manuscript received November 13, 2010; revised March 15, 2011 and May 09, 2011; accepted May 10, 2011. Date of publication June 27, 2011; date of current version August 17, 2011. This work was supported by the COCAE FP7 Project (http://www.cocae.eu)., The Vertical Gradient Freeze (VGF) method has been used to grow high resistivity Cadmium Zinc Telluride (CZT) for high energy radiation applications. In this work, the effect of lapping and polishing the lateral edges of planar detectors is studied. Expectations that improved surface morphology of the edges should correlate with reduced surface leakage current are shown to be erroneous. The effect of various types of lateral edge treatments on detector performance was observed before and after each surface modification. Complementary results were obtained using I-V, Cathodoluminescence (CL), and gamma ray response measurements using 133Ba. As a result, a quick and easy method is reported which minimizes leakage current and actually enhances detector performance through the introduction of surface defects. It is demonstrated that the introduction of radiative recombination centers helps reduce surface leakage current in the detector by a factor of up to 200%, depending on the surface treatment. The purpose of this work is to identify material processing steps for fabricating planar devices based on CZT for gamma ray spectroscopy., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2001 Elsevier Science B.V. Spring Meeting of the European-Materials-Research-Society (2000. Strasbourg, Francia). This work has been supported by CICYT under the project ESP-98-1340., In this work pure and Gd-doped GaSb ingots with different dopant concentrations were grown by the Bridgman Method. The compositional and electrical analysis carried out on these materials have shown the dependence of these results on the initial dopant concentration. The analysis have revealed the presence of inclusions which have been identified as Gd-Sb precipitates. The doped material was found to be p-type with a maximum value of the carrier density at the central region of the ingots. It has been also demonstrated that the Gd enhances the A band emission reducing the band-gap emission., CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 1999 American Institute of Physics. This work was supported by DGES (Project No. PB96-0639) and by CICYT (Project Nos. ESP95-0148 and ESP98-1340), Er 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 been found to be about 0.5 eV while in undoped crystals the gap is close to the bulk value. Inhomogeneities in the local electronic properties of the doped crystals are studied by a correlation of the CL images and STS data., DGES, CICYT, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© CENIM Los autores agradecen al MICINN la financiación recibida a través de los proyectos MAT2006-11202 y MAT2009-14452., The microstructure and mechanical properties in the interface region of a multilayer laminate based on high strength aluminium alloys, Al 7075 and Al 2024, have been characterized mainly by EBSD and shear tests. It is shown that the time of solution treatment during T6 thermal treatment modifies the microstructure of the constituent alloys adjacent to the interface and, as a consequence, the interfacial mechanical properties. The combination of the correct rolling processing with optimized thermal treatment leads to strong interfaces prone to delaminate, and thus, materials with outstanding mechanical properties., MICINN, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2005 IOP Publishing Ltd. This work was supported by MEC (Project MAT 2003-00455) and CAM (Project GR/MAT 630-04)., Thermal 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 nanoneedles. Enhanced cathodoluminescence emission is associated with the wires and needles, which show a component at 2.72 eV not observed. for the untreated material., MEC, CAM, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2004 IOP Publishing Ltd. International Workshop on Beam Injection Assessment of Microstructures in Semconductors. (7. 2003. Lille. Francia). This work was sponsored by CNRS/ADEME (France), by Conseils Regional (PACA) and General (13)-France and by Secretaria General Educacion y Universidades (Spain)., By means of a contactless microwave phase shift technique, the minority carrier lifetime and surface recombination velocity were measured in multicrystalline silicon wafers containing iron and chromium. The bulk lifetime can be deduced, leading to the determination of the concentration of interstitial iron [Fe-i] associated with boron, after pair dissociation annealing at 210 degreesC. It is found that [Fe-i] is higher in the vicinity of extended defects but decreases at the defects because the iron segregates irrespective of boron concentration and does not form pairs., CNRS/ADEME (France), Conseils Regional (PACA), General (13)-France, Secretaria General Educacion y Universidades (Spain)., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

© 2004 IOP Publishing Ltd. International Workshop on Beam Injection Assessment of Microstructures in Semiconductors (7. 2003. Lille,Francia)., The cathodoluminescence (CL) technique is used to analyse the radiative recombination properties of four distinct silicon carbide (SiC) samples: a 6H-SiC n^+ -type Lely wafer, two off-axis 4H-SiC epitaxial layers of n type and p type, and a (11 (2) over bar0)-oriented 4H-SiC n^+-type substrate. The CL spectra, recorded at various temperatures and at various excitation conditions, show strong differences between the polytypes, indicating a better homogeneous distribution of radiative centres inside the 6H polytype than in the 4H one, and also between the different orientations. For the (11 (2) over bar0)-oriented 4H sample, luminescence features decrease when the excitation intensity increases, probably due to a more significant indirect transition band. The CL spectra also vary for the same sample, due to the impurity and the microscopic defect density variations. Comparisons between two local spectra taken in two distinct areas of the (11 (2) over bar0)-oriented 4H sample, and with images obtained by x-ray topography in the same areas, allow us to establish that some structural defects are involved in luminescence centres. A deep centre involved in green luminescence (at 1.80 eV) is found to be associated with basal plane dislocations with the Burgers vector b = (1/3)(11 (2) over bar0)., Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

CRUE-CSIC (Acuerdos Transformativos 2022) ©2022 WILEY-V C H VERLAG GMBH This work has been supported by MINECO projects M-ERA.NET PCIN-2017-106 and MICINN project (RTI2018-097195-B-I00). We thank the CAI (UCM) for XRD facilities., Zn_2GeO_4 microrods obtained by thermal evaporation of a compacted powder mixture of ZnO and Ge exhibit quite intense UV luminescence at low temperatures. Herein, the luminescence properties of Zn_2GeO_4 microrods are studied for 2:1 and 1:1 ZnO:Ge ratio in the precursor mixture. In both cases, Zn2GeO4 microrods of high crystal quality produce a 355 nm emission under aforementioned bandgap excitation conditions at low temperatures. However, this emission vanishes at room temperature (RT) in the 1:1 samples while it is kept in the 2:1 ones. Herein this work, the thermal quenching of the UV luminescence is studied by means of steady and time-resolved photoluminescence techniques from 4 K up to RT for both Zn_2GeO_4 microrods. The analysis of the results leads us to conclude that although the luminescence mechanisms are the same in both cases, a higher decay rate is observed in the 1:1 in both intensity and lifetime, which explain the observed thermal quenching at RT., Ministerio de Ciencia e Innovación (MICINN)/ FEDER, Ministerio de Ciencia e Innovación (MICINN)/M-ERA.Net, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

In this PhD thesis work, the results obtained from the research on micro- and nanostructuresof zinc germanate (Zn2GeO4) are shown and discussed. This material is a wide bandgapsemiconductor, member of the transparent conducting oxide (TCO) family, which presentsseveral physical properties that make it a potential candidate for its integration in differentoptoelectronic or energy storage devices.The scope of applications of Zn2GeO4 can be extended or improved by controllingthe dimensions and morphology, as well as intrinsic defects and doping with impurities.Therefore, in this work, different synthesis or growth methods were employed in orderto achieve Zn2GeO4 structures with the desired dimensions, morphologies and physicalproperties. Thus, by means of the physical growth method of thermal evaporation, usingthe vapor-solid (VS) mechanism, both elongated Zn2GeO4 micro- and nanostructures wereobtained. This method was also used to dope the Zn2GeO4 structures by diffusion, includingthe dopant impurities during the growth stage. On the other hand, Zn2GeO4 nanocrystalswere synthesized via the chemical precipitation method..., En el presente trabajo de tesis doctoral se muestran y discuten los resultados obtenidos durante la investigación realizada con micro- y nanoestructuras de germanato de zinc(Zn2GeO4). Este material es un semiconductor de gap ancho que forma parte de la familia de los óxidos conductores transparentes (TCO), y el cual presenta una serie de propiedades físicas que lo convierten en un potencial candidato para su incorporación en diversos dispositivos optoelectrónicos o de almacenamiento energético. El campo de aplicaciones del Zn2GeO4 se puede ampliar o mejorar mediante el control delas dimensiones y morfología, así como de los defectos intrínsecos y dopado con impurezas. Por ello, en este trabajo se emplearon diferentes métodos de síntesis o crecimiento, con el fin de lograr estructuras de Zn2GeO4 con las dimensiones, morfologías y propiedades físicas deseadas. Así, mediante el método de crecimiento físico de evaporación térmica, empleado el mecanismo vapor-sólido (VS), se obtuvieron tanto micro- y nanoestructuras alargadas de Zn2GeO4 como estructuras complejas. Este método fue también utilizado para doparlas estructuras de Zn2GeO4 mediante difusión, al incluir las impurezas dopantes durante la etapa de crecimiento. Por otro lado, se sintetizaron nanocristales de Zn2GeO4 a través del método de precipitación química...

In this PhD thesis work, the results obtained from the research on micro- and nanostructuresof zinc germanate (Zn2GeO4) are shown and discussed. This material is a wide bandgapsemiconductor, member of the transparent conducting oxide (TCO) family, which presentsseveral physical properties that make it a potential candidate for its integration in differentoptoelectronic or energy storage devices.The scope of applications of Zn2GeO4 can be extended or improved by controllingthe dimensions and morphology, as well as intrinsic defects and doping with impurities.Therefore, in this work, different synthesis or growth methods were employed in orderto achieve Zn2GeO4 structures with the desired dimensions, morphologies and physicalproperties. Thus, by means of the physical growth method of thermal evaporation, usingthe vapor-solid (VS) mechanism, both elongated Zn2GeO4 micro- and nanostructures wereobtained. This method was also used to dope the Zn2GeO4 structures by diffusion, includingthe dopant impurities during the growth stage. On the other hand, Zn2GeO4 nanocrystalswere synthesized via the chemical precipitation method...

©2020 Royal Society of Chemistry The authors acknowledge funding support from Spanish Ministry of Science and Innovation through projects MAT2015-65274-R/FEDER, RTI2018-097195-B-I00 and M-ERA.NET PCIN-2017-106., The growth mechanism of layered alpha-MoO_3 nano- and microplates on the surface of Mo wires during Joule heating has been investigated by application of an external electric field to the current carrying wire. The observed rapid growth of the structures, involving enhanced diffusion processes associated to the intense electric current, is further enhanced by the external field leading to a near instantaneous formation of MoO_3 plates. Thermally assisted electromigration in the Mo wire with the additional effect of the electric field appears as a very time effective method to grow MoO_3 layered low dimensional structures. Other molybdenum oxide nanostructures, such as nanospheres and nanocrystallites with different shapes, have been found to grow by deposition from the Mo wire on the electrodes used to apply the external electric field. The growth on the electrodes takes place by a thermally assisted electric-field-driven process., Ministerio de Ciencia e Innovación (MICINN), Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub

©2020 Elsevier This work has been supported by MINECO/FEDER (MAT201565274-R)., The properties of ZnO based materials for ethanol detection have been studied. Cu doped samples obtained from different precursors have been investigated. ZnO and ZnS have been used as host and Cu and CuO as dopant sources. The sensing measurements have been mostly performed at room temperature. To monitor the effect of the presence of gas, resistivity and photoluminescence experiments with and without sensing gas have been carried out. The sensing behaviour is affected by the nature of the precursors used. For ZnO:Cu and ZnO:CuO series, a higher sensitivity is obtained at the lower gas concentrations, the better response is obtained for the sample ZnO:Cu with wt.1% of metallic copper. Strong segregation effects observed in these samples could be deleterious for the sensing properties. In the series ZnS:CuO, no segregation is observed, however the sensing behaviour is erratic and attributed to the reduction of Cu ions to the metallic state., Ministerio de Economía y Competitividad (MINECO)/ FEDER, Depto. de Física de Materiales, Fac. de Ciencias Físicas, TRUE, pub