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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Growth of EuTe islands on SnTe by molecular beam epitaxy

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Diaz, B. [1] ; Malachias, A. [2] ; Rappl, P. H. O. [1] ; Abramof, E. [1] ; Chitta, V. A. [3] ; Henriques, A. B. [3]
Total Authors: 6
[1] Inst Nacl Pesquisas Espaciais, Lab Associado Sensores & Mat, BR-12227010 Sao Jose Dos Campos, SP - Brazil
[2] Lab Nacl Luz Sincrotron, BR-13083970 Campinas, SP - Brazil
[3] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Journal of Crystal Growth; v. 312, n. 19, p. 2828-2833, SEP 15 2010.
Web of Science Citations: 3

Semiconductor magnetic quantum dots are very promising structures, with novel properties that find multiple applications in spintronic devices. EuTe is a wide gap semiconductor with NaCl structure, and strong magnetic moments S=7/2 at the half filled 4f(7) electronic levels. On the other hand, SnTe is a narrow gap semiconductor with the same crystal structure and 4% lattice mismatch with EuTe. In this work, we investigate the molecular beam epitaxial growth of EuTe on SnTe after the critical thickness for island formation is surpassed, as a previous step to the growth of organized magnetic quantum dots. The topology and strain state of EuTe islands were studied as a function of growth temperature and EuTe nominal layer thickness. Reflection high energy electron diffraction (RHEED) was used in-situ to monitor surface morphology and strain state. RHEED results were complemented and enriched with atomic force microscopy and grazing incidence X-ray diffraction measurements made at the XRD2 beamline of the Brazilian Synchrotron. EuTe islands of increasing height and diameter are obtained when the EuTe nominal thickness increases, with higher aspect ratio for the islands grown at lower temperatures. As the islands grow, a relaxation toward the EuTe bulk lattice parameter was observed. The relaxation process was partially reverted by the growth of the SnTe cap layer, vital to protect the EuTe islands from oxidation. A simple model is outlined to describe the distortions caused by the EuTe islands on the SnTe buffer and cap layers. The SnTe cap layers formed interesting plateau structures with easily controlled wall height, that could find applications as a template for future nanostructures growth. (C) 2010 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 08/04329-9 - Magnetic Nanostructures of Europium Telluride
Grantee:Beatriz Leonila Díaz Moreno
Support Opportunities: Scholarships in Brazil - Post-Doctorate