Extended x-ray absorption fine structure study of AlxGa(1−x)N films

Abstract

Extended x-ray absorption fine structure above the Ga–K edge has been used to study the local structure of AlxGa1−xN films grown by metal organic chemical vapor deposition. With increasing Al content, x, the Ga–N bond length decreases, but much less than the average bond length. On the other hand, the x dependence of the Ga–Ga and Ga–Al distances does follow the variation of the average cation–cation distance. We conclude that bond angle distortions accommodate the differences between the Ga–N and Al–N bond lengths.

Coupling of GaN- and AlN-like longitudinal optic phonons in Ga1−xAlxN solid solutions

“…One obtains the impurity mode frequencies ͑AlN:Ga͒ϭ600 cm Ϫ1 and ͑GaN:Al͒ϭ655 cm Ϫ1 , using 0.7 for the bond relaxation rate. 13 the Grüneisen parameters were taken from Refs. 14 and 15.…”

Statistical model of sphalerite structured quaternary A1−xBxYyZ1−y systems

“…This was the first well-documented information about SOPs from next nearest-neighbours (NNN) for ternary III-V and II-VI alloys. Additional EXAFS studies have been performed in CdHgTe [15], CdMnTe [16], CdZnTe [17], GaAlN [18], GaAsP [19], GaInAs [20], HgMnTe [15], HgZnTe [21], ZnMnS [22][23][24], ZnMnSe [25,26] and ZnMnTe [27], while FIR spectra have been collected for CdHgTe [28], CdSeTe [29] and CdZnTe [30]. All these alloys clearly exhibit occupation preferences.…”

Spontaneous polarization in III‐nitride materials: crystallographic revision

“…First, the alloys lattice constants obey very accurately the Vegard law. Second, it has been shown experimentally by extended X-ray absorption fine structure (EXAFS) technique that the mean distances between anions and cations in AlGaN and InGaN alloys are much closer to those in their binary constituents than to the values predicted by the Vegard law [8,9]. Since charge transfer from cation to anion is largely controlled by atomic terms of the individual ions and interatomic distances [10], the EXAFS data imply the cation effective charges in the alloy to be nearly the same as in the respective binary compounds.…”