Atomic and electronic structures of interfaces of complex oxides: insight from ab initio calculations
EMSL Project ID
42315
Abstract
Oxide interfaces, superlattices and solid solutions provide opportunities for generating materials with novel properties. A critical issue is to control the quality of the interfaces and atom ordering. Current growth techniques have limited capabilities of controlling atomic scale processes and even post factum characterization of the interface disorder is difficult. In this regards, accurate predictions of thermodynamically stable interface structures, characterization of the interface structural disorder and its effect on the interface electronic properties would provide valuable complementary information and will guide further experimental work. Previous research has demonstrated that epitaxial film growth can be used to generate single interfaces and quasi-two-dimensional materials with novel properties. However, there is little understanding of the effects of cross-interface atom diffusion and structural disorder on the interface electronic properties. The primary objective of this project is to unravel the atomic scale mechanisms governing modification of the electronic properties of interfaces of two complex oxides upon inter-diffusion of metal atoms across the plane of the interface. We will focus on LaCrO3 (LCO) and LaFeO3 (LFO) interfaces. These materials are antiferromagnets, but their multilayers can exhibit ferromagnetism in some cases. In this project we will apply a range of empirical and ab initio computational methods in order to investigate the effect of the cation interdiffusion and lattice defects, such as anion vacancies and nitrogen substitutional impurities, on the electronic and magnetic structures of LFO/LCO interfaces and pinpoint the mechanisms of control over the interface properties.
Project Details
Project type
Exploratory Research
Start Date
2010-10-06
End Date
2011-10-09
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Chambers SA, L Qiao, T Droubay, TC Kaspar, BW Arey, and PV Sushko. 2011. "Band Alignment, Built-In Potential, and the Absence of Conductivity at the LaCrO3/SrTiO3(001) Heterojunction." Physical Review Letters 107(20):Article No. 206802. doi:10.1103/PhysRevLett.107.206802
Chambers SA, MH Engelhard, V Shutthanandan, Z Zhu, T Droubay, L Qiao, PV Sushko, T Feng, HD Lee, T Gustafsson, E Garfunkel, AB Shah, JM Zuo, and QM Ramasse. 2010. "Instability, intermixing and electronic structure at the epitaxial LaAlO3/SrTiO3(001) heterojunction." Surface Science Reports 65(10-12):317-352. doi:10.1016/j.surfrep.2010.09.001
Qiao L, T Droubay, TC Kaspar, PV Sushko, and SA Chambers. 2011. "Cation mixing, band offsets and electric fields at LaAlO3/SrTiO3(001) heterojunctions with variable La:Al atom ratio." Surface Science 605(15-16):1381-1387. doi:10.1016/j.susc.2011.04.035
Qiao L, T Droubay, V Shutthanandan, Z Zhu, PV Sushko, and SA Chambers. 2010. "Thermodynamic Instability at the Stoichiometric LaAlO3/SrTiO3(001) Interface." Journal of Physics. Condensed matter 22(31):Art. No. 312201. doi:10.1088/0953-8984/22/31/312201
Sushko PV. 2012. "Tuning Optical Properties of Complex Oxides: Examples of 12CaO.7Al2O3 Mayenite and LaCrO3 Perovskite." In Oxide-based Materials and Devices III, vol. 8263, ed. Ferechteh H. Teherani; David C. Look; David J. Rogers, pp. 8263-34. Proceedings of SPIE, Bellingham, WA. doi:10.1117/12.912844