Joan ESTEVE PUJOL | Universitat de Barcelona (original) (raw)

Papers by Joan ESTEVE PUJOL

Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1987

CuInSe2 thin films were deposited onto glass and liquid-indium-coated glass substrates by coevapo... more CuInSe2 thin films were deposited onto glass and liquid-indium-coated glass substrates by coevaporation of copper, indium, and selenium. The morphology, composition, and crystalline properties have been studied in relation to the deposition process parameters. The deposition rate and the grain size are higher in films grown on liquid indium than on glass and depend on the indium film thickness. Films grown on indium do not show the same crystalline phases of films grown on glass, and in order to obtain films free of spurious phases the Cu fluxes must be increased.

Diamond and Related Materials, 2000

To pursue single-crystal diamond growth on silicon substrates, the mechanism of diamond nucleatio... more To pursue single-crystal diamond growth on silicon substrates, the mechanism of diamond nucleation and growth must be well Ž. Ž. understood. For this purpose, step-by-step depositions of hydrocarbon species on a silicon 001-2 = 1 surface were simulated based on a series of calculations using semi-empirical molecular orbital PM3 and density-functional theories. Molecular mechanics was also used to optimize the interface structure of a large cluster model in order to reveal the interface strain and Ž. bonding. It is shown that diamond can be coincidentally built on the silicon 001 surface in spite of the 3:2 lattice mismatch. Issues such as residual lattice mismatch, nucleation mode and surface roughness relating to single-crystal diamond growth are discussed.

Physical Review Letters, 2008

We report on the generation, subsequent oscillation and interaction of a pair of matter wave dark... more We report on the generation, subsequent oscillation and interaction of a pair of matter wave dark solitons. These are created by releasing a Bose-Einstein condensate from a double well potential into a harmonic trap in the crossover regime between one dimension (1D) and three dimensions (3D). Multiple oscillations and collisions of the solitons are observed, in quantitative agreement with simulations of the Gross-Pitaevskii equation. An effective particle picture is developed and confirms that the deviation of the observed oscillation frequencies from the asymptotic prediction νz/ √ 2, where νz is the longitudinal trapping frequency, results from the dimensionality of the system and the soliton interactions.

MRS Proceedings

In this work, thin films (thickness ∼ 0.5 μm) were obtained by plasma polymerization of pyrrole (... more In this work, thin films (thickness ∼ 0.5 μm) were obtained by plasma polymerization of pyrrole (Ppy) and thiophene (Pth) at 25-30 W and 0.1-0.2 mbar of pressure. Further doping with iodine was carried out to some of the Ppy and Pth films (Ppy/I2, Pth/I2) in order to enhance their electrical conductivity properties.Structural and morphological characterization of both Ppy and Pth as well as of Ppy/I2 and Pth/I2 was performed using Infrared Spectroscopy (IR), X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM).In the light of the information given by IR, XPS and AFM techniques, exhaustive and accurate description of both undoped and I2/doped Ppy and Pth films obtained by Plasma Polymerization is attained.

Revista UIS Ingenierías

La combinación de materiales cerámicos y metálicos en estructuras multicapa es bien conocida por ... more La combinación de materiales cerámicos y metálicos en estructuras multicapa es bien conocida por producir recubrimientos con un comportamiento mecánico y tribológico mejorado. En este artículo, reportamos las propiedades tribológicas de recubrimientos multicapa de cromo/carburo de cromo Cr/CrC nanométricos depositados por pulverización catódica magnetrón r.f. Las pruebas de fricción y desgaste en deslizamiento fueron desarrolladas sobre multicapas de Cr/CrC también como sobre recubrimientos de referencia de CrC. El comportamiento al desgaste en deslizamiento en seco de las multicapas de Cr/CrC fue investigado usando la técnica de esfera sobre disco con contra cuerpos esféricos de alúmina y acero. Los recubrimientos multicapa exhibieron resistencia al desgaste en deslizamiento en seco mejor que el de referencia. Las multicapas de Cr/CrC mostraron coeficientes de fricción en seco entre 0,50 y 0,60 y la monocapa de CrC alrededor de 0,30 a lo largo de toda la prueba. Los principales mecanismos de desgaste en deslizamiento son discutidos.

physica status solidi (b)

Goya Revista De Arte, 2001

Xi Congreso De Conservacion Y Restauracion De Bienes Culturales Castellon 3 4 5 Y 6 De Octubre De 1996 1996 Isbn 84 86895 79 0, 1996

Ceramics International, 2016

The influence of single and repetitive sudden changes of temperature on the mechanical integrity ... more The influence of single and repetitive sudden changes of temperature on the mechanical integrity of cemented carbides was investigated as a function of their microstructure. Thermal shock resistance was assessed by testing the residual flexural strength of hardmetal beams after being subjected to thermal shock by water quenching. Results indicate that hard cemented carbides tend to exhibit a superior resistance to the nucleation of thermal shock damage but a lower resistance to the propagation of thermal shock than tough cemented carbides, and vice versa. These trends are in agreement with those expected from the evaluation of the thermal shock Hasselman's parameters. The evidenced strength loss after thermal shock may be related to the subcritical growth of intrinsic 1 Current address: Sandvik Mining and Construction Tools AB. Västberga, Stockholm 0120, Sweden. 2 flaws based on localized microcracking. Results also point out on Ni-based hardmetals to exhibit a slightly higher resistance to abrupt changes of temperature than Co-based ones.

Revista Eia, Sep 26, 2013

Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto

J. Mater. Chem. A, 2015

A novel synthetic strategy based on the controlled corrosion of silver templates allows us to pre... more A novel synthetic strategy based on the controlled corrosion of silver templates allows us to prepare PtAg@Pt single-crystal hollow NCs with high-index planes at room temperature with enhanced surface reactivity.

Revista Facultad de Ingeniería

Dyna (Medellin, Colombia)

En aquest treball presentem l'obtenció de diferents nanopartícules inorgàniques i l'estud... more En aquest treball presentem l'obtenció de diferents nanopartícules inorgàniques i l'estudi de les seves interaccions com a mecanisme d'estudi per al desenvolupament de nous materials avançants. També presentem la hibridació de nanopartícules amb molècules biològiques en aplicacions clíniques.

Surface and Coatings Technology, 1998

The aim of this work is to study both the mechanical and the structural properties of yttria-stab... more The aim of this work is to study both the mechanical and the structural properties of yttria-stabilized zirconia (YSZ) coatings prepared on metallic substrates. YSZ films were obtained in a hot wall MOCVD reactor using Zr(thd), and Y(thd), as organometallic precursors. The evaporation and the deposition temperatures were chosen in order to stabilize the cubic phase of the zirconia. The coatings were produced on different nickel and chromium alloys substrates. X-ray diffraction and SIMS techniques were used to characterize the influence of different experimental parameters, such as substrate nature. deposition temperature and thermal treatment, on the structure and composition of the YSZ film and the film/substrate interface. Mechanical properties of the coatings were also determined, before and after heat treatment, by means of microindentation tests. 8 1998 Elsevier Science S.A.

Journal of Vacuum Science & Technology B, 1996

Electron beam deposition ͑EBD͒ provides an inexpensive way to fabricate nanostructures of various... more Electron beam deposition ͑EBD͒ provides an inexpensive way to fabricate nanostructures of various materials in a scanning electron microscope ͑SEM͒. However, the purity of metals deposited from an organometallic precursor gas is impaired by simultaneously deposited carbon coming both from the organometallic molecule and the residual contamination gas in the SEM chamber. We discuss carbon-contamination EBD in a standard high-vacuum SEM and compare it to EBD of Au in an environmental SEM ͑ESEM͒. The ESEM allowed us to perform ''environmental'' EBD ͑E-EBD͒, i.e., EBD in the presence of an environmental gas ͑1-10 Torr͒ in addition to the organometallic precursor gas. We built a simple device that contains a reservoir for the organometallic precursor and goes on the sample stage of the ESEM. With this device we were able to highlight the advantages of E-EBD over conventional, high-vacuum EBD. We discuss the basic chemical reactions underlying the E-EBD process.

Zeitschrift für Physikalische Chemie, 2015

The design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanc... more The design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanced functionalities, comprising both hybrid and hollow structures, and the study of their fundamental properties is of paramount importance for the development of a new generation of nanostructured materials. The possibility of tailoring the dimensional regime of NCs, along with its composition and structure, represents a landmark achievement in the control of their unique physico-chemical properties. These properties, alongside with the ability to cheaply produce high quality NCs in fairly large amounts by wetchemistry techniques, leads to their potential applicability from materials science to nanomedicine. Within this context, this review is focused on describing a successful framework for designing synthetic strategies for the production of advanced complex NCs, integrating the development of new synthetic methods with its structural characterization, monitoring of their properties, and study of its reactivity. As a result, it is expected to provide new routes to produce robust and easy-to-process NCs in a wide range of sizes, shapes and configurations that can be explored to achieve the combination of all degrees of control, aiming to produce a complete and diverse library of material combinations that will expand its applicability in a wide diversity of fields.