Abstract
In this article, we study the possible relation between the electronic and magnetic structures of the TiO2/LaAlO3 interface and the unexpected magnetism found in undoped TiO2 films grown on LaAlO3. We concentrate on the role played by structural relaxation and interfacial oxygen vacancies. LaAlO3 has a layered structure along the (001) direction with alternating LaO and AlO2 planes, with nominal charges of +1 and −1, respectively. As a consequence of that, an oxygen-deficient TiO2 film with anatase structure will grow preferently on the AlO2 surface layer. We have therefore performed ab initio calculations for superlattices with TiO2/AlO2 interfaces with interfacial oxygen vacancies. Our main results are that vacancies lead to a change in the valence state of neighbor Ti atoms but not necessarily to a magnetic solution and that the appearance of magnetism depends also on structural details, such as second neighbor positions. These results are obtained using both the local spin density approximation (LSDA) and LSDA + U approximations.
Similar content being viewed by others
References
Matsumoto Y, Shono T, Hasegawa T, Fukumura T, Kawasaki M, Ajmet P, Chikyow T, Koshihara S, Koinuma H (2001) Science 291:854
Venkatesan M, Fitzgerald CB, Lunney JG, Coey JMD (2004) Phys Rev Lett 93:177206
Janisch R, Gopal P, Spaldin NA (2005) J Phys Condens Matter 17:R657
Duhalde S, Vignolo MF, Golmar F, Chilotte C, Torres CER, Errico L, Cabrera AF, Renteria M, Sanchez F, Weissmann M (2005) Phys Rev B 72:R161313
Venkatesan M, Fitzgerald CB, Coey JMD (2004) Nature 430:630
Yoon SD, Chen Y, Yang A, Goodrich TL, Zuo X, Ziemer K, Vittoria C, Harris V (2007) J Mag Mag Mater 309:171
Hassini A, Sakai J, Lopez JS, Hong NH (2008) Phys Lett A 372:3299
Chambers SA (2006) Surf Sci Rep 61:345
Sudakar C, Kharel P, Suryanarayanan R, Thakur JS, Naik VM, Naik R, Lawes G (2008) J Mag Mag Mater 320:L31
Errico L, Renteria M, Weissmann M (2005) Phys Rev B 72:184425
Weissmann M, Errico L (2007) Physica B 398:179
Pacchioni G (2008) J Chem Phys 128:182505 and references therein
Kim D, Hong J, Park YR, Kim KJ (2009) J Phys Condens Matter 21:195405
Weissmann M, Ferrari V (2009) J Phys Conf Ser 167:012060
Eglitis RI, Vanderbilt D (2007) Phys Rev B 76:155439
Eglitis RI, Vanderbilt D (2008) Phys Rev B 77:195408
Park MS, Rhim SH, Freeman AJ (2006) Phys Rev B 74:205416
Pentcheva R, Pickett WE (2008) Phys Rev B 78:205106
Hohenberg P, Kohn W (1964) Phys Rev 136:B864
Blaha P, Schwarz K, Madsen GKH, Kvasnicka D, Luitz J (2001) WIEN2k, an augmented plane wave + local orbitals program for calculating crystal properties. Karlheinz Schwarz, Techn. Universitt Wien, Austria (ISBN 3-9501031-1-2)
Perdew JP, Wang Y (1992) Phys Rev B 45:13244
Anisimov VI, Solovyev IV, Korotin MA, Czyzyk MT, Sawatzky GA (1993) Phys Rev B 48:16929
Morgan BJ, Watson GW (2007) Surf Sci 601:5034
Rumaiz A, Ali B, Ceylan B, Boggs M, Beebe T, Ismat Shah S (2007) Solid State Commun 144:334
Acknowledgement
We acknowledge the support by CONICET under Grant PIP 112-200801-38, ANPCyT under Grant PICT-06-157, and a CNRS-CONICET International Scientific Cooperation Project (PICS).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Weissmann, M., Ferrari, V. & Saúl, A. Ab initio study of magnetism at the TiO2/LaAlO3 interface. J Mater Sci 45, 4945–4951 (2010). https://doi.org/10.1007/s10853-010-4231-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-010-4231-z