The role of 2D islands in the epitaxial growth of (001) CdTe

We present an extensive study of the homoepitaxial growth of (001) CdTe with a particular emphasis on the variation of the lattice parameter and on the determination of the surface stoichiometry during the growth as well as the related evolution of the growth rate. An oscillatory behavior of the in plane lattice parameter during the 2D homoepitaxial growth of (001) CdTe is demonstrated. It is associated to a deformation, induced by the surface reconstructions, at the free edges of the small islands formed during the growth by molecular beam epitaxy (MBE) or atomic layer epitaxy. During the MBE growth, the presence on top of the CdTe growing surface of both chemisorbed dimerized tellurium atoms and weakly bonded Te atoms adsorbed on top of this Te layer is evidenced. The influence of the stoichiometry on the evolution of the growth rate is demonstrated. Moreover, an influence of strain on the growth mechanisms of CdTe has been observed

Heteroepitaxial growth of InAs on GaAs(100) mediated by Te at the interface

The heteroepitaxy of InAs on a Te covered GaAs surface is investigated by photoelectron spectroscopy. Core-level spectra probed with synchrotron radiation show that Te remains at the interface between InAs and GaAs in a concentration much higher than the solubility limit of this element in III-V compounds, suggesting that a new compound is being formed. We propose that this interlayer is responsible for the observed changing in the growth mode of the InAs overlayer from islands to layer by layer

Anisotropic magnetic-field-induced phase transition in MnAs nanoribbons

MnAs thin films present a phase coexistence of regularly arranged ferromagnetic (alfa) and paramagnetic (beta) stripes below the Curie temperature when grown onto GaAs(100) substrates. In this letter, we report the observation of a magneto-structural phase transition induced by magnetic field on MnAs nanoribbons below the Curie temperature. A transformation of high-resistance paramagnetic regions into low-resistance ferromagnetic ones is observed above temperature-dependentcritical magnetic fields. The phenomenon is hysteretic, highly anisotropic, and size dependent and could be the origin of the high magneto-resistance effect observed at temperatures close to room temperature in these systems.Fil: Fernandez Baldis, Federico Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Fundación José A. Balseiro; ArgentinaFil: Sirena, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Fundación José A. Balseiro; ArgentinaFil: Steren, Laura Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Etgens, V.H.. Universite de Paris Vi. Institut des Nanosciences de Paris; FranciaFil: Eddrief, M.. Universite de Paris Vi. Institut des Nanosciences de Paris; FranciaFil: Ulysse, C.. Centre National de la Recherche Scientifique; FranciaFil: Faini, G.. Centre National de la Recherche Scientifique; Franci