Structural Basis for the Conducting Interface between LaAlO{sub 3} and SrTiO{sub 3}

Journal Article · Fri Oct 12 00:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.99.155502· OSTI ID:21024268

Willmott, P R; Pauli, S A; Herger, R; Schlepuetz, C M; Martoccia, D; Patterson, B D; Delley, B ^[1]; Clarke, R; Kumah, D; Cionca, C ^[2]; Yacoby, Y ^[3]

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1. Paul Scherrer Institut, CH-5232 Villigen (Switzerland)
2. Randall Laboratory of Physics and FOCUS Center, University of Michigan, Ann Arbor, Michigan 48109-1120 (United States)
3. Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel)

The complete atomic structure of a five-monolayer film of LaAlO{sub 3} on SrTiO{sub 3} has been determined for the first time by surface x-ray diffraction in conjunction with the coherent Bragg rod analysis phase-retrieval method and further structural refinement. Cationic mixing at the interface results in dilatory distortions and the formation of metallic La{sub 1-x}Sr{sub x}TiO{sub 3}. By invoking electrostatic potential minimization, the ratio of Ti{sup 4+}/Ti{sup 3+} across the interface was determined, from which the lattice dilation could be quantitatively explained using ionic radii considerations. The correctness of this model is supported by density functional theory calculations. Thus, the formation of a quasi-two-dimensional electron gas in this system is explained, based on structural considerations.

• OSTI ID: 21024268
• Journal Information: Physical Review Letters, Vol. 99, Issue 15; Other Information: DOI: 10.1103/PhysRevLett.99.155502; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINATES
ATOMIC RADII
DENSITY FUNCTIONAL METHOD
ELECTRON GAS
ELECTRONIC STRUCTURE
INTERFACES
LANTHANUM COMPOUNDS
MINIMIZATION
STRONTIUM TITANATES
THIN FILMS
TITANIUM IONS
TWO-DIMENSIONAL CALCULATIONS
X-RAY DIFFRACTION