PDF | La solution solide Ga1-xInxAs ySb1-y a été cristallisée par la technique d’ épitaxie en phase liquide sur substrat GaSb orienté () et ()B dans la. Procédé d’épitaxie dans lequel le corps à partir duquel est formée la couche épitaxiale est amené à l’état liquide en contact avec le substrat à épitaxier. Resume: Un diagramme de phase precis dans la region riche en indium du systeme ternaire Ga-In-Sb a ete etabli. Les points du liquidus ont ete obtenus par .
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Epitaxial growth of gallium oxide films on c-cut sapphire substrate. Toward a complete description of nucleation and growth in liquid-liquid phase separation. Effects of substrate and ambient gas on epitaxial growth indium oxide thin films.
Oriented metallic nano-objects on crystalline surfaces by solution epitaxial growth. Nanoselective area growth of gan by metalorganic vapor phase epitaxy on 4h-sic using epitaxial graphene as a mask. Bulk ppktp by crystal growth from high temperature solution. Epitaxial growth of gold on mica in an ultra-high vacuum.
Diagramme de phases et croissance par epitaxie en phase liquide du gaxin1-xsb
Toggle navigation Share your values. Un diagramme de phase precis dans la region riche en indium du systeme ternaire Ga-In-Sb a ete etabli. Les points du liquidus ont ete obtenus par analyse thermique differentielle d’echantillons de composition determinee. Les points du solidus resultent de la mesure de la concentration en gallium de cristaux ternaires epitaxies a partir de liquides riches en indium.
Les isothermes du liquidus et les courbes solidus ont ete calcules sur epitxaie modele des solutions regulieres. En ajustant certains parametres thermodynamiques, l’accord obtenu avec les points experimentaux est excellent cote indium du diagramme ternaire. Des couches de GaxIn1-xSb de 0 x 0,92 ont ete epitaxiees sur substrats d’InSb orientes dans la gamme de temperatures Epitaxif.
L’homogeneite et les autres caracteristiques de ces couches ont ete examinees. Quelques resultats de mesures electriques sont fournis. Share with your friends and colleagues. Epitaxial growth of gallium oxide films on c-cut sapphire substrate W. The nature of the crystalline phase present in gallium oxide films grown by pulsed-laser deposition on c-cut sapphire substrate has been studied. Amorphous, polycrystalline or epitaxial gallium oxide films can be obtained depending upon the oxygen pressure during the growth in the C temperature range.
Two distinct textures were evidenced, i. The corresponding epitaxial relationships were determined and interpreted in the frame of the domain phaee epitaxy. The differences in the two textures were correlated to the various atomic configurations in the and planes of the monoclinic -Ga2O3 phase. Growth of epitaxial tungsten nanorods R. A simple vapour deposition technique was used to prepare WO3 one-dimensional nanostructures.
WO3 is sublimated at a pnase low temperature in air at atmospheric pressure. The sublimated species are condensed on mica substrate at 1C. Single crystalline nanorods are grown in epitaxy on the mica surface with a growth axis along directions and plane parallel to the substrate. A epiatxie process is proposed liquidd which the formation of a onedimensional tetragonal tungsten bronze as precursor is the determining factor.
Toward a complete description of nucleation and growth in liquid-liquid phase separation J. The phase separation mechanism of a binary liquid mixture off-critically quenched in its miscibility gap is nucleation and growth, its homogeneous phase reaching a metastable equilibrium state.
The successive stages of growth of the nucleated droplets are a diffusion-driven free growth, eh intermediate regime and a coarsening by reduction of interface. We have made light attenuation experiments to investigate the sedimentation in such systems.
These results have given us access experimentally to two values predicted theoretically: These data, added to the literature results, have permitted to get a quite complete view of the growth scenario in very off-critical phase-separating liquids.
Effects of substrate and ambient gas on epitaxial growth indium oxide thin films M. Indium oxide thin films were grown by pulsed electron beam deposition method at C on c-cut sapphire and oriented LaAlO3 single crystal substrates in oxygen or argon gas. The effects of ambient gas and substrate symmetry on the growth of indium oxide thin films were studied.
Stoichiometric In2O3 films are formed in oxygen, while oxygen deficient In2O2. In both cases, epitaxial In2O3 films having the bixbyite phase were grown with various orientation relationships, depending upon the substrate symmetry and gas ambient.
Domain matching epitaxy was used to describe the precise in-plane epitaxial film-substrate relationships. The differences in film texture were correlated to the differences in growth conditions, while the differences in the film properties were correlated to the film oxygen composition. Oriented metallic nano-objects on crystalline surfaces by solution epitaxial growth N. Chemical methods offer the possibility to synthesize a large panel of nanostructures of various materials with promising properties.
One of the main limitations to a mass market development of nanostructure based devices is the integration at a moderate cost of nano-objects into smart architectures. Here we develop a general approach by adapting the seed-mediated solution phase synthesis of nanocrystals in order to directly grow them on crystalline thin films.
Diagramme de phases et croissance par epitaxie en phase liquide du gaxin1-xsb
Using a Co precursor, single-crystalline Co nanowires are directly grown on metallic films and present different spatial orientations depending on the crystalline symmetry of the film used as a 2D seed for Co nucleation.
Using films exposing 6-fold symmetry surfaces such as PtAuand Cothe Co heterogeneous nucleation and epitaxial growth leads to vertical nanowires self-organized in dense and large scale arrays. On the other hand, using films presenting 4-fold symmetry surfaces such as Pt and Cuthe Co growth leads to slanted wires in discrete directions.
This approach of solution epitaxial growth combines the advantages of chemistry in solution in producing shape-controlled and monodisperse metallic nanocrystals, and of seeded growth on an ad hoc metallic film that efficiently controls orientation through epitaxy. It opens attractive opportunities for the integration of nanocrystals in planar devices. An arrangement for measuring the thermoelectric voltage Seebeck signal during the crystal growth from a liquid zone is described.
Using the example of growing PbTe single crystals by THM it is shown that different equilibrium temperatures at both phase boundaries provide a differential Seekeck voltage depending on the crystal growth rate.
Relaxation times which are needed to reach steady-state conditions with respect to the concentration difference between the growing and solving interface in the case of a start or sudden stop of the heater motion can be obtained. Nanoselective area growth of gan by metalorganic vapor phase epitaxy on 4h-sic using epitaxial graphene as a mask G. We report the growth of high-quality triangular GaN nanomesas, nm thick, on the C-face of 4H-SiC using nano selective area growth with patterned epitaxial graphene grown on SiC as an embedded mask.
NSAG alleviates the problems of defective crystals in the heteroepitaxial growth of nitrides, and the high mobility graphene film can readily provide the back low-dissipative electrode in GaN-based optoelectronic devices. The process consists in first growing a graphene layers film on the C-face of 4H-SiC by confinement-controlled sublimation of silicon carbide.
The graphene film is then patterned and arrays of nanometer-wide openings are etched in graphene revealing the SiC substrate. GaN nanomesas grow epitaxially with perfect selectivity on SiC, in openings patterned through graphene, with no nucleation on graphene. The up-or-down orientation of the mesas on SiC, their triangular faceting, and cross-sectional scanning transmission electron microscopy show that they are biphasic.
The core is a zinc blende monocrystal surrounded with single-crystal hexagonal wurtzite. The GaN crystalline nanomesas have no threading dislocations, and do not show any V-pit.
Bulk ppktp by crystal growth from high temperature solution C. Periodically-poled ferroelectric crystals show unprecedented efficiency and properties otherwise impossible to obtain. Unfortunately, the sample thickness obtainable today limits their use to low and moderate power application. With the aim of increasing the size of periodically domain-structured crystals with a controlled and regular grating period, we proposed an epitaxial growth process using seeds made of thin plates domain engineered by electric field poling.
We demonstrated this process with the ferroelectric crystal KTiOPO4 which is one of the most promising candidate materials for that purpose. The poling step requires a sample exhibiting and over bar faces, so that the growth step has to be performed onto these faces. This constraint is a difficulty to circumvent as these faces are not present in the standard equilibrium morphology. It is then necessary to find the growth conditions enabling to work below the roughening temperature of these faces.
By using a high temperature solution method, the so-called “flux method”, and by choosing an appropriate chemical composition of the flux solution, we obtained periodically domain-structured KTP layers with thicknesses up to mu m and regular periodicity onto and over bar faces of the initial PPKTP seeds.
Epitaxial growth of gold on mica in an ultra-high vacuum H. The effect of adsorbed gas on the growth of gold films on mica at epitaxial temperatures is investigated by comparing the growths on air exposed and vacuum cleaved mica surfaces. Evaporations at residual gas pressures of 3 x mm Hg are employed to make films with optical thicknesses of 10 A.
Optical and electron transmission examinations show that adsorbed gas drastically effects the initial growth of the film.