The crystalline structure of thin bismuth layers grown on silicon (111) substrates
| Autor: | Sandra Stanionytė, Tadas Malinauskas, Gediminas Niaura, Martynas Skapas, Jan Devenson, Arūnas Krotkus |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Materials, Basel : MDPI AG, 2022, vol. 15, iss. 14, art. no. 4847, p. 1-12 Materials; Volume 15; Issue 14; Pages: 4847 |
| ISSN: | 1996-1944 |
| Popis: | Bismuth films with thicknesses between 6 and ∼30 nm were grown on Si (111) substrate by molecular beam epitaxy (MBE). Two main phases of bismuth — α-Bi and β-Bi — were identified from high-resolution X-ray diffraction (XRD) measurements. The crystal structure dependencies on the layer thicknesses of these films were analyzed. β-Bi layers were epitaxial and homogenous in lateral regions that are greater than 200 nm despite the layer thickness. Further, an increase in in-plane 2θ values showed the biaxial compressive strain. For comparison, α-Bi layers are misoriented in six in-plane directions and have β-Bi inserts in thicker layers. That leads to smaller (about 60 nm) lateral crystallites which are compressively strained in all three directions. Raman measurement confirmed the XRD results. The blue-sift of Raman signals compared with bulk Bi crystals occurs due to the phonon confinement effect, which is larger in the thinnest α-Bi layers due to higher compression. |
| Databáze: | OpenAIRE |
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