Applying surface-sensitive techniques to structural and chemical study of uncapped Sn-Sb-Te thin film. A density functional theory - based study
| Autor: | Vitaliy Bilovol, Leonardo A. Errico, H.H. Medina Chanduví |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Metals and Alloys Analytical chemistry chemistry.chemical_element Surfaces and Interfaces Surfaces Coatings and Films Electronic Optical and Magnetic Materials Pulsed laser deposition Antimony chemistry X-ray photoelectron spectroscopy Phase (matter) Materials Chemistry Density functional theory Thin film Spectroscopy Tin |
| Zdroj: | Thin Solid Films. 736:138909 |
| ISSN: | 0040-6090 |
| Popis: | We present here a combined experimental and theoretical study of the structural and chemical properties of polycrystalline Sn-Sb-Te film with nominal composition SnSb2Te4 grown by pulsed laser deposition technique on mylar substrate. From the experimental side, surface-sensitive techniques as x-ray photoelectron spectroscopy (XPS), grazing incidence x-ray diffractometry (GIXRD) and 119mSn integral conversion electron Moβbauer spectroscopy (ICEMS) have been applied to the study of the film at room-temperature and under normal conditions of pressure. GIXRD showed that the Sn-Sb-Te film adopted a NaCl- type structure (Fm-3m), and in the detection limits, no other crystalline phase was revealed. ICEMS technique unambiguously indicated the coexistence of two different tin fractions: Sn(II), as expected for the SnSb2Te4 phase, and Sn(IV), suggesting oxidation of tin. Chemical in-depth profile obtained by means of XPS suggests the oxidation of all the constituent atoms at the topmost layers of the film and the progressive depletion of tin and antimony oxides going depth in the film. The in-depth atomic concentration profiles also reveals a notorious deficiency of Te in the sample. Theoretically, density functional theory-based calculations (assuming that the Sn-Sb-Te film adopts the Fm-3m structure) support the hypothesis that Te - vacancies sites are occupied by oxygen atoms during the natural oxidation process of Sn-Sb-Te film. Additionally, our calculations demonstrated that only the substitution of Te atoms by oxygen ones induces a semiconducting behavior of the otherwise metallic Sn-Sb-Te host. |
| Databáze: | OpenAIRE |
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