Lattice Parameter and Density in Germanium-Silicon Alloys¹

Abstract

The lattice parameter and density of chemically analyzed samples of homogeneous Ge-Si alloy have been measured throughout the entire alloy system. The temperature dependence of the lattice parameter was measured from 25 to 800°. Compositional dependences of the lattice parameter and density are accurate to about ±0.3 atomic % in alloy composition. Lack of chemical analysis or sample inhomogeneity may explain the large discrepancies between previous investigations of these properties. The excess volume of mixing is given by AFmxs = -0.24c<>eCsi cm.8 mole-1. Deviations from Vegard's law are negative as predicted by models based on first-order elasticity theory, but smaller in absolute magnitude. This discrepancy is about the size of the positive deviations calculated from second-order elasticity theory.

Germanium Silicon Alloy Anode Material Capable of Tunable Overpotential by Nanoscale Si Segregation

“…Representatively, the XRD peak of the (111) plane appears at 27.47°in Type-U SiGe NW, which corresponds to a lattice constant of 5.6120 Å (Figure 2b). The chemical composition calculated from the lattice constant based the result of Dismukes et al 24 is Ge 0.85 Si 0.15 , which is also corroborated by EDX result of ∼14 at % Si (Supporting Information Figure S1a). As shown in Figure 2b, a nonnegligible peak shift to lower 2θ was observed after thermal annealing.…”

Influence of Experimental Parameters on the Determination of Tetragonal Distortion in Heterostructures by LACBED

“…N. x ( 1 + v ) / ( 1-v), N being the atomic density and x is the Ge atomic fraction. It comes out that (3 = (7.0 ib 0.7) x 10-25 cm3at-1, which is lower than that foreseen by the Vegard's law ((3 = 8.34 x 10-25 cm3 at-1 ) and agrees with the one reported by Dismukes et al [7]. This confirms that ELACBED is practically coincident with ~T.…”

“…The values of the various parameters, relative to the measured contours in the sample SIGE1, are reported in Table II. Given a kinematical contour, ELACBED can be obtained from equation (4). These values are plotted in Figure 5 as a function of the germanium concentration in the films, which has been [7], is deduced.…”

Defect interactions in Sn1−xGex random alloys

“…1,3 Although the structure and defect processes in diamondtype random alloys such as Si 1−x Ge x have received considerable attention, the structure of Sn 1−x Ge x has not, so far, been investigated in detail. [4][5][6][7][8] Previous density functional theory ͑DFT͒ studies were confined to predicting the structure of ordered Sn 1−x Ge x alloys. 9 Here we adopt the so-called special quasirandom structure ͑SQS͒ approach 10 to mimic the statistics of random Sn 1−x Ge x alloys at compositions x = 0.875, 0.75, and 0.625, respectively ͑see Fig.…”