A study of the reactivity of elemental Cr/Se/Te thin multilayers using X-ray reflectometry, in situ X-ray diffraction and X-ray absorption spectroscopy

Journal Article · Wed Nov 15 00:00:00 EST 2006 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2006.06.024· OSTI ID:20900875

Behrens, Malte ^[1]; Tomforde, Jan ^[1]; May, Enno ^[1]; Kiebach, Ragnar ^[1]; Bensch, Wolfgang ^[1]; Haeussler, Dietrich ^[2]; Jaeger, Wolfgang ^[2]

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1. Institute of Inorganic Chemistry, Christian-Albrechts-University of Kiel, Olshausenstr. 40-60, 24098 Kiel (Germany)
2. Mikrostrukturanalytik, Technische Fakultaet, Christian-Albrechts-University of Kiel, Kaiserstr. 2, 24143 Kiel (Germany)

The reactivity of [Cr/Se/Te] multilayers under annealing was investigated using X-ray reflectometry, in situ X-ray diffraction, X-ray absorption fine structure (XAFS) measurements and transmission electron microscopy. For all samples, interdiffusion was complete at temperatures between 100 and 300 deg. C, depending on the repeating tri-layer thickness. A crystalline phase nucleated approximately 20 deg. C above the temperature where interdiffusion was finished. The first crystalline phase in a binary Cr/Te sample was layered CrTe{sub 3} nucleating at 230 deg. C. In ternary samples (Se:Te=0.6-1.2), the low-temperature nucleation of such a layered CrQ {sub 3} (Q=Se, Te) phase is suppressed and instead the phase Cr{sub 2} Q {sub 3} nucleates first. Interestingly, this phase decomposes around 500 deg. C into layered CrQ {sub 3}. In contrast, binary Cr/Se samples fstable amorphous alloys after interdiffusion and Cr{sub 3}Se{sub 4} nucleates around 500 deg. C as the only crystalline phase. Evaluation of the XAFS data of annealed samples yield Se-Cr distances of 2.568(1) and 2.552(1) A for Cr{sub 2} Q {sub 3} and CrQ {sub 3}, respectively. In the latter sample, higher coordination shells around Se are seen accounting for the Se-Te contacts in the structure. - Graphical abstract: The first step of the reaction of elemental Cr/Te/Se-multilayers is the interdiffusion of the elements as evidenced by the decay of the modulation peaks in the low-angle region of the X-ray diffraction patterns. The subsequent growth of Bragg peaks at higher scattering angles indicates crystallization of chromium chalcogenide Cr{sub 2}Te{sub 3-} {sub x} Se {sub x}.

• OSTI ID: 20900875
• Journal Information: Journal of Solid State Chemistry, Vol. 179, Issue 11; Other Information: DOI: 10.1016/j.jssc.2006.06.024; PII: S0022-4596(06)00367-7; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
ABSORPTION SPECTROSCOPY
ANNEALING
BRAGG CURVE
CHROMIUM
CHROMIUM ALLOYS
CHROMIUM SELENIDES
CHROMIUM TELLURIDES
CRYSTALLIZATION
FINE STRUCTURE
LAYERS
SELENIUM
TELLURIUM
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY