The presence of 2D electron gases at surfaces or interfaces in oxide thin films remains a hot topic in condensed matter physics. In particular, BaBiO3 appears as a very interesting system as it was theoretically proposed that its (001) surface should become metallic if a Bi-termination is achieved (Vildosola et al., PRL 110, 206805 (2013)). Here we report on the preparation by pulsed laser deposition and characterization of BaBiO3 thin films on silicon. We show that the texture of the films can be tuned by controlling the growth conditions, being possible to stabilize strongly (100)-textured films. We find significant differences on the spectroscopic and transport properties between (100)-textured and non-textured films. We rationalize these experimental results by performing first principles calculations, which indicate the existence of electron doping at the (100) surface. This stabilizes Bi ions in a 3+ state, shortens Bi-O bonds and reduces the electronic band gap, increasing the surface conductivity. Our results emphasize the importance of surface effects on the electronic properties of perovskites, and provide strategies to design novel oxide heterostructures with potential interface-related 2D electron gases. © 2016 Author(s).
Documento: | Artículo |
Título: | Tuning the electronic properties at the surface of BaBiO3 thin films |
Autor: | Ferreyra, C.; Guller, F.; Marchini, F.; Lüders, U.; Albornoz, C.; Leyva, A.G.; Williams, F.J.; Llois, A.M.; Vildosola, V.; Rubi, D. |
Filiación: | GIyA y INN, CNEA, Av.Gral Paz 1499, San Martín, Buenos Aires, 1650, Argentina Departamento de Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina Departamento de Química Inorgánica, Analítica y Química-Física, INQUIMAE-CONICET, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires, Argentina CRISMAT, CNRS UMR 6508, ENSICAEN, 6 Boulevard Maréchal Juin, Caen Cedex 4, 14050, France Escuela de Ciencia y Tecnología, UNSAM, Campus Miguelete, San Martín, Buenos Aires, 1650, Argentina |
Palabras clave: | Barium compounds; Calculations; Condensed matter physics; Electron gas; Electronic properties; Energy gap; Film preparation; Interfaces (materials); Oxide films; Perovskite; Pulsed laser deposition; Semiconductor doping; Electron-doping; Electronic band gaps; First-principles calculation; Growth conditions; Oxide heterostructures; Oxide thin films; Surface conductivity; Surface effect; Thin films |
Año: | 2016 |
Volumen: | 6 |
Número: | 6 |
DOI: | http://dx.doi.org/10.1063/1.4954037 |
Título revista: | AIP Advances |
Título revista abreviado: | AIP Adv. |
ISSN: | 21583226 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_21583226_v6_n6_p_Ferreyra |