Search results for "reflection"
showing 10 items of 645 documents
Accurate and precise lattice parameters by selected-area electron diffraction in the transmission electron microscope
2009
8 páginas, 6 figuras, 7 tablas.
Interaction of oxygen with Mo(100), Mo(110), and Mo(111) surfaces. RHEED and AES analyses of the molybdenum oxide nucleation and growth
1991
Abstract A study of the nucleation and growth of MoO 3 generated by interaction of oxygen with Mo(100), Mo(110), and Mo(111) single crystalline surfaces is investigated at high oxygen pressure (10 4 Pa) and low temperature (620 to 820 K). The results of RHEED and AES analyses prove that under these oxidation conditions, MoO 3 nucleates directly from the metal without intermediate formation of MoO 2 or nonstoichiometric molybdenum oxide such as Mo 4 O 11 . The structure and orientation of MoO 3 nuclei are characterized in relation with the parent molybdenum surface. On the Mo(110) and Mo(111) surfaces, which are faceting, the nucleation and growth of MoO 3 takes place by successive structura…
Morphology and magnetoresistance of Co2Cr0.6Fe0.4Al-based tunnelling junctions
2009
Some ferromagnetic Heusler compounds are theoretically predicted to be half metallic materials, i.e. to be characterized by a huge spin polarization at the Fermi energy. We investigate the correlations between junction preparation conditions, morphology and transport properties of planar MgO/Co2Cr0.6Fe0.4Al/AlOx/Co/CoOx/Pt tunnelling junctions. Epitaxial Co2Cr0.6Fe0.4Al thin films were deposited by dc and rf magnetron sputtering on different buffer layers (Cr, Fe, MgO) on MgO(1 0 0) substrates. By RHEED, LEED and in situ STM investigations different surface morphologies were observed. Atomically flat surfaces with Co2Cr0.6Fe0.4Al unit cell sized steps (B2 structure) were obtained by rf sput…
Electron Diffraction Reinvestigation of CdCr<sub>2</sub>Se<sub>4</sub> and ZnCr<sub>2-x</sub>V<sub>x</su…
2013
Crystal structure of two spinel single crystals CdCr2Se4 and ZnCr2-xVxSe4 have been reinvestigated using automated electron diffraction tomography method with beam precession. 3D reciprocal space have been reconstructed base on recorded tilt series. For both samples crystal structure was refined and the cubic symmetry with space group Fd-3m was confirmed. No additional electron potential has been located beside occupied atom sites.
Ex situ investigations of MOCVD-grown gallium nitride nanowires using reflection high energy electron diffraction
2011
Vertically oriented nanowires (NWs) of single-crystalline wurtzite GaN have been fabricated on sapphire substrates, via metal organic chemical vapor deposition (MOCVD). We present ex situ investigations on orientation and structure of grown GaN nanowires on GaN(0001) surface using reflection high energy electron diffraction (RHEED). Both ordered and randomly oriented GaN crystalline structures have been detected.
La enseñanza del verbo y la actividad metalingüística de los alumnos. Dos investigaciones en aulas de Secundaria
2021
La investigación en Didáctica de la lengua persigue entender las relaciones entre la perspectiva de la enseñanza, la perspectiva del aprendizaje y la de los contenidos trabajados en el aula de Lengua. Este artículo pone el foco en el verbo como contenido gramatical a partir de dos investigaciones centradas en la actividad metalingüística de los alumnos de Educación Secundaria Obligatoria. En la primera, los estudiantes intentan explicar las diferencias entre los tiempos verbales del pasado como paso previo para utilizarlos en la escritura. En la segunda, la reflexión se centra en el subjuntivo a partir de una actividad de pares mínimos que tiene como objetivo comprender cómo conceptualizan …
Structural Characterization of Monolayers at the air-water interface
1991
Racialized immigrants becoming part of the city : connecting migration, space and race : commentary to van Liempt
2023
Building on Ilse van Liempt’s (2023) lecture, this commentary addresses the connection and shift between forced displacement and local emplacement by addressing what becoming part of the city means for racialized immigrants. By bringing forward the notion of racialization I hope to contribute to a growing body of literature discussing how malleable and productive the concept of race – albeit erased and relegated to the past – keeps on shaping conversations about and across Europe. Connecting migration, space and race offers a particularly rich context in which to have this discussion because, as all three elements are mutually constructive, addressing them together exposes some of the compl…
Orders of Consciousness and Forms of Reflexivity in Descartes
2007
Erratum to “Irregularity” [Topology Appl. 154 (8) (2007) 1565–1580]
2012
[2, Proposition 4.4] states that each regular pretopology is topologically regular. Professor F. Mynard (Georgia Southern University) advised the authors that he was not convinced by the proof of that proposition, which enabled us to realize the proposition is wrong, as the example below shows. Recall that (e.g., [2]) a pretopology ξ on a set X is called regular if Vξ (x)⊂ adh ξ Vξ (x) (respectively, topologically regular if Vξ (x)⊂ cl ξ Vξ (x)) for every x ∈ X . As a consequence, in the sequel of [2], regular should be read topologically regular in a few instances, in particular in [2, Theorem 4.6]. [2, Proposition 4.4] is also quoted in [3], where it is used in some reformulations of clas…