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Interfacial properties of perovskite thin films

English title Interfacial properties of perovskite thin films
Applicant Willmott Philip
Number 117615
Funding scheme Project funding (Div. I-III)
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Condensed Matter Physics
Start/End 01.10.2007 - 30.11.2011
Approved amount 193'992.00
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All Disciplines (2)

Discipline
Condensed Matter Physics
Material Sciences

Keywords (6)

Perovskite; Complex metal oxide; Interface ; Thin film ; Surface x-ray diffraction; Pulsed laser deposition

Lay Summary (English)

Lead
Lay summary
The surfaces of crystalline materials have, in general, a different structure from that found within the bulk of the same material. The main reason for this is that, in forming a surface, bonds must be broken, which leaves electrons "dangling" out of the surface. These will redistribute themselves to create the lowest energy surface, which inevitably results in the atoms also rearranging themselves to a greater or lesser extent.

This surface rearrangement (called a "relaxation" if the movements are only in or out of the surface, and "reconstructions" if lateral movements in the plane of the surface are also present) can have fundamental influences on the physical properties of the material in this surface region. This is especially true for so-called "strongly correlated electron systems", where even the subtlest structural changes can bring about very large changes in the physical and electronic properties.

One problem in identifying how structural changes effect the physical properties is that it is very difficult to quantitatively see what the shifts in the atomic positions are. Even movements of as little as 1 picometer (1 millionth of 1 millionth of a meter), or an angular tilt in bond directions of less than 1 degree can be crucially important. Essentially, there is only one technique capable of providing the necessary accuracy, and this is Surface X-Ray Diffraction (SXRD).

In this project, we have studied the surface and interface structures of ultrathin films of La-Sr-Mn-O (LSMO) using SXRD. LSMO changes its resistivity by several orders of magnitude, depending on the strength of any external field it may be in, and therefore very interesting as a data storage medium. In this project, we want to see if there is a minimum thickness of thin film, below which this effect vanishes, and how this is related to changes in the thin film and interface structure.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Angle calculations for a (2+3)-type diffractometer: focus on area detectors
Schleputz CM, Mariager SO, Pauli SA, Feidenhans'l R, Willmott PR (2011), Angle calculations for a (2+3)-type diffractometer: focus on area detectors, in JOURNAL OF APPLIED CRYSTALLOGRAPHY, 44, 73-83.
Electrostriction at the LaAlO3/SrTiO3 Interface
Cancellieri C, Fontaine D, Gariglio S, Reyren N, Caviglia AD, Fete A, Leake SJ, Pauli SA, Willmott PR, Stengel M, Ghosez P, Triscone JM (2011), Electrostriction at the LaAlO3/SrTiO3 Interface, in PHYSICAL REVIEW LETTERS, 107(5), 056102-1-056102-4.
Evolution of the Interfacial Structure of LaAlO3 on SrTiO3
Pauli SA, Leake SJ, Delley B, Bjorck M, Schneider CW, Schleputz CM, Martoccia D, Paetel S, Mannhart J, Willmott PR (2011), Evolution of the Interfacial Structure of LaAlO3 on SrTiO3, in PHYSICAL REVIEW LETTERS, 106(3), 036101-1-036101-4.
Structure of ultrathin heteroepitaxial superconducting YBa2Cu3O7-x films
Schleputz CM, Bjorck M, Koller E, Pauli SA, Martoccia D, Fischer O, Willmott PR (2010), Structure of ultrathin heteroepitaxial superconducting YBa2Cu3O7-x films, in PHYSICAL REVIEW B, 81(17), 174520-1-174520-9.

Collaboration

Group / person Country
Types of collaboration
University of Geneva Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure

Associated projects

Number Title Start Funding scheme
137507 Direct Methods Applied to Oxide Heterostructures 01.01.2012 Project funding (Div. I-III)
111750 Initial Growth Modes of Perovskite Thin Films 01.04.2006 Project funding (Div. I-III)
146015 The physics of conducting interfaces in insulating heterostructures 01.05.2013 Project funding (Div. I-III)
126901 The physics of conducting interfaces in insulating heterostructures 01.05.2010 Project funding (Div. I-III)

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