Bi-Stability and Orientation Change of a Thin α‑Fe2O3 Layer on a ε‑Fe2O3 (004) Surface
| Autor: | Heon-Jung Kim, Nam-Suk Lee, Yusuff Adeyemi Salawu |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: | |
| Zdroj: | ACS Omega, Vol 4, Iss 8, Pp 13330-13337 (2019) ACS Omega |
| ISSN: | 2470-1343 |
| Popis: | This study reports the key ingredients that influence the orientation and stability of a α-Fe2O3 layer that grows on a metastable ε-Fe2O3 during pulsed laser deposition. Depending on the substrate temperature, two different α-Fe2O3 orientations arise on the ε-Fe2O3 (004) surface. At 800 °C, (2–10)α-oriented α-Fe2O3 is stabilized, whereas at 700 °C, (006)α orientation occurs. The (2–10)α-oriented α-Fe2O3 layer possesses an interface with densely packed Fe ions with presumably considerable number of oxygen vacancies. On the other hand, the (006)α-oriented α-Fe2O3 layer is stabilized, as in the case of the YSZ (100) substrate, due to the domain pattern with an in-plane rhombic shape, which is known to become an effective nucleation site. Growth with the unexpected (2–10)α orientation can be understood based on a model that takes into account the surface energy as the dominant factor, which mainly stems from the presence of dangling bonds on the surface and the atomic vibration of the surface atoms. As the surface is one of the critical elements related to the specific functionality of a material, the present study will offer valuable insights into the designs of functional devices with novel surface properties. |
| Databáze: | OpenAIRE |
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