Leiden University Scholarly Publications

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Torren, A.J.H. van der (2016)

Growing oxide thin films in a low-energy electron microscope

Doctoral Thesis

 

By combining low-energy electron microscopy (LEEM) with pulsed laser deposition (PLD), we have created a unique set-up to study the first stages of growth of complex metal oxides. We demonstrate this by investigating the growth of SrTiO3 (STO) and LaAlO3 (LAO) on STO in real-time.
We follow growth by monitoring the intensity and the full-width-half-maximum (FWHM) of the specular diffracted beam at various energies. For layer-by-layer growth, we find the anticipated intensity peaks at the completion of each layer, and an oscillatory FWHM with the maximum at half-layer coverage.
In the LAO on STO case, for optimal growth conditions and a LAO thickness above the critical thickness of 4 unit cells the interface between the band insulators shows conductivity.
We obtain an electronic fingerprint of the growing material, by measuring the...

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By combining low-energy electron microscopy (LEEM) with pulsed laser deposition (PLD), we have created a unique set-up to study the first stages of growth of complex metal oxides. We demonstrate this by investigating the growth of SrTiO3 (STO) and LaAlO3 (LAO) on STO in real-time.
We follow growth by monitoring the intensity and the full-width-half-maximum (FWHM) of the specular diffracted beam at various energies. For layer-by-layer growth, we find the anticipated intensity peaks at the completion of each layer, and an oscillatory FWHM with the maximum at half-layer coverage.
In the LAO on STO case, for optimal growth conditions and a LAO thickness above the critical thickness of 4 unit cells the interface between the band insulators shows conductivity.
We obtain an electronic fingerprint of the growing material, by measuring the intensity of the specular beam as a function of energy at regular intervals during growth. Extending this fingerprint with the intensity dependence on the momentum parallel to the surface allows us to extract the band dispersion of unoccupied electron states of the sample surface.
Significant differences in the unoccupied band structure develop between samples which are conducting and non-conducting.

 

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Low-energy electron microscopy
LEEM
Pusled laser deposition
PLD
LaAlO3
SrTiO3
All authors
Torren, A.J.H. van der
Supervisor
Aarts, J.
Co-supervisor
Molen, S.J. van der
Committee
Dittmann, R.; Rijnders, A.J.H.M.; Caviglia, A.; Eliel, E.R.; Oosterkamp, T.H.
Qualification
Doctor (dr.)
Awarding Institution
Leiden Institute of Physics (LION), Science, Leiden University
Date
2016-12-05
Title of host publication
Casimir PhD Series
ISBN (print)
9789085932765

Publication Series

Name
2016-32

Funding

Sponsorship
The work described in this thesis is supported by the Netherlands Organisation for Scientific Research (NWO) by means of a ”NWO Groot” grant and by the Leiden-Delft Consortium NanoFront. The work is part of the research programmes NWOnano and DESCO, administered by the Foundation for Fundamental Research on Matter (FOM), which is part of NWO.