Résumé | The atomic density of amorphous SixGe1−x alloys (0 x 1), has been measured. The amorphous alloys were made by high-ion-energy implantation into monocrystalline SixGe1−x layers, deposited epitaxially on silicon substrates. During the bombardments, a steel contact mask was used to create alternating lines of amorphous and crystalline material. The ratio between the densities of crystalline and amorphous alloys was measured with 0.1–0.2% accuracy using surface profilometry and Rutherford backscattering spectrometry in conjunction with channelling. Amorphous pure elements and alloys are less dense by 1.5–2.1% than the crystalline pure elements and alloys. By comparing both the amorphous and crystalline densities with Vegard's law, it is found that this law underestimates the a-SixGe1−x densities by the same amount as those of c-SixGe1−x. |
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