English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/10431
Share/Impact:
Statistics
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:

Title

Surface characterization of Mn(x)Ge(1−x) and Cr(y)Mn(x)Ge(1−x−y) dilute magnetic semiconductors

AuthorsGambardella, Pietro; Claude, L.; Rusponi, S.; Franke, K. J.; Brune, H.; Raabe, J.; Nolting, F.; Bencok, Peter; Hanbicki, A. T.; Jonker, B. T.; Grazioli, C.; Veronese, M.; Carbone, Carlo
KeywordsManganese compounds
Chromium compounds
Semimagnetic semiconductors
Ferromagnetic materials
Paramagnetic materials
Magnetic moments
X-ray photoelectron spectra
X-ray absorption
Semiconductor epitaxial layers
Fluorescence
Etching
Surface composition
Magnetic circular dichroism
Oxidation
Segregation
Issue Date28-Mar-2007
PublisherAmerican Physical Society
CitationPhysical Review B 75(12): 125211 (2007)
AbstractWe have used x-ray photoemission electron microscopy (XPEEM) and x-ray absorption spectroscopy (XAS) to characterize Mn(x)Ge(1−x) and Cr(y)Mn(x)Ge(1−x−y) films grown by molecular beam epitaxy. The surface layers of the as-grown films probed by XPEEM present segregation of Mn-rich phases. XAS using both total electron yield and fluorescence yield detection shows that the films are heavily oxidized after exposure to air. Etching in HF and HCl can be used to reduce oxidation, but inhomogeneities in the surface composition might not be completely eliminated depending on the Mn concentration. X-ray magnetic circular dichroism (XMCD) measurements reveal that neither the etched nor the as-grown films present remanent ferromagnetic behavior down to a temperature of 5 K within the probing depth of the fluorescence yield (~20 nm). Mn is paramagnetic in both the oxidized and etched samples, with an increased tendency to order magnetically toward the interior of the films. Cr in Cr(y)Mn(x)Ge(1−x−y) possesses a paramagnetic moment only in the oxidized form. A comparison of the XAS line shapes obtained in the present study with those of Mn impurities deposited on Ge and GaAs surfaces demonstrates that the interpretation of XAS spectra of Mn-doped dilute magnetic semiconductors in the literature is often affected by residual oxidation.
Description7 pages, 7 figures.-- PACS nrs.: 75.50.Pp; 75.70.-i; 78.70.Dm; 75.20.Hr.
Publisher version (URL)http://dx.doi.org/10.1103/PhysRevB.75.125211
URIhttp://hdl.handle.net/10261/10431
DOI10.1103/PhysRevB.75.125211
ISSN1098-0121
Appears in Collections:(CIN2) Artículos
Files in This Item:
File Description SizeFormat 
PRB75_125211.pdf829,91 kBAdobe PDFThumbnail
View/Open
Show full item record
Review this work
 

Related articles:


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.