Electronic and crystal structure changes induced by in-plane oxygen vacancies in multiferroicYMnO3

Abstract

The widely spread oxygen vacancies $({V}_{\mathrm{O}})$ in multiferroic materials can strongly affect their physical properties. However, their exact influence has rarely been identified in hexagonal manganites. Here, with the combined use of transmission electron microscopy (TEM) and first-principles calculations, we have systematically studied the electronic and crystal structure modifications induced by ${V}_{\mathrm{O}}$ located at the same Mn atomic plane (in-plane ${V}_{\mathrm{O}})$. Our TEM experiments reveal that the easily formed in-plane ${V}_{\mathrm{O}}$ not only influence the electronic structure of $\mathrm{YMn}{\mathrm{O}}_{3}$ but alter the in-plane Wyckoff positions of Mn ions, which may subsequently affect the intraplane and interplane exchange interaction of Mn ions. The ferroelectricity is also impaired due to the introduction of ${V}_{\mathrm{O}}$. Further calculations confirm these electronic and structural changes and modifications. Our results indicate that the electronic and crystal structure of $\mathrm{YMn}{\mathrm{O}}_{3}$ can be manipulated by the creation of ${V}_{\mathrm{O}}$.