Local crystal structure in the vicinity of Cr in doped AlN thin films studied by X-ray absorption spectroscopy
This article reports the detailed X-ray absorption spectroscopy (XAS) study of Al 1− x Cr x N ( x = 4, 6, 11%) thin films synthesized by the reactive magnetron co-sputtering technique. All these films were crystallized with a hexagonal wurtzite structure with preferential orientation along the a -ax...
Saved in:
Published in | Physical chemistry chemical physics : PCCP Vol. 2; no. 18; pp. 1384 - 1391 |
---|---|
Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
England
Royal Society of Chemistry
2018
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | This article reports the detailed X-ray absorption spectroscopy (XAS) study of Al
1−
x
Cr
x
N (
x
= 4, 6, 11%) thin films synthesized by the reactive magnetron co-sputtering technique. All these films were crystallized with a hexagonal wurtzite structure with preferential orientation along the
a
-axis without the formation of any secondary phases. Surface chemical analysis to evaluate the Cr concentration was carried out using X-ray photoelectron spectroscopy. The study confirmed the presence of AlN and Cr in bonding with N. The local crystal structure around the Cr dopant in the as-synthesized and annealed thin films has been analyzed by both the X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) techniques. From XAS, it was found that Cr replaced the Al atom in the AlN lattice and led to a localized CrN species with distorted tetrahedral AlN in the absence of Cr clustering. The bond lengths of (Cr-N)
ax
, (Cr-N)
bs
and Cr-Al, extracted from the EXAFS fitting, were found to decrease with the Cr concentration for both the as-synthesized and annealed thin films due to the enhancement of p-d hybridization between the dopant and the host atoms. However, in the annealed 11% Cr film, the bond lengths are larger than the other and tend to match the Cr-N geometry in CrN.
This article reports the detailed X-ray absorption spectroscopy (XAS) study of Al
1−
x
Cr
x
N (
x
= 4, 6, 11%) thin films synthesized by the reactive magnetron co-sputtering technique. |
---|---|
Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1463-9076 1463-9084 |
DOI: | 10.1039/c8cp01686k |