Quadruple-period ordering along [110] in aGaAs0.87Sb0.13alloy

Abstract

A quantitative structural model, based on x-ray diffraction, is provided to analyze quadruple-period atomic ordering along ͓110͔ in a GaAs 0.87 Sb 0.13 alloy grown on a ͑001͒ GaAs substrate by molecular beam epitaxy. To minimize the local strain energy derived by a valence force field ͑VFF͒ model for the alloy, atomic displacements were deduced and incorporated in our model. Calculation of the scattering pattern based on the model agrees well with experiment. We propose that this ordering originates from a (2ϫ4) surface reconstruction and the difference in properties of the atomic species.

X-ray characterization of atomic-layer superlattices

“…On the atomic scale, the occupational defects are often randomly distributed, resulting in a reduction of the degree of ordering [5]. These defects can also exist on a larger scale, leading to antiphase domains [5,6]. The domain structure alters the phase of the scattered x-rays and consequently the peak position and intensity.…”

Anisotropic resistivity correlated with atomic ordering in p-type GaAsSb

“…3,4 Ordering types including CuAu-I (L1 0 ), CuPt (L1 1 ), and chalcopyrite (E1 1 ) have been reported in GaAsSb for growth on a variety of substrates and crystallographic orientations. [9][10][11] The particular surface reconstruction is likely a factor in the growth process. [9][10][11] The particular surface reconstruction is likely a factor in the growth process.…”

Determination of the order parameter of CuPt-B ordered GaInP2 films by x-ray diffraction

“…␦ i is a complex function of s and can be obtained independently from a valence force field ͑VFF͒ model calculation. 12,14 For CuPt-B ordered GaInP 2 , we found that the difference in length between the In-P and the Ga-P bonds is mainly accommodated by the displacement of P atoms. The displacement of In and Ga atoms is significantly smaller.…”

“…The method can be extended to other types of ordering in semiconductor alloys, e.g., triple-and quadrupleperiod ordered systems where modulation of the peak intensity due to atomic displacements has been observed by both x-ray diffraction 14 …”