Kelvin Probe Force Microscopy Study of LaAlO3/SrTiO3 Heterointerfaces

Vladimir Popok, Alexey Kalabukhov, Robert Gunnarsson, Sergey Lemeshko, Tord Claeson, Dag Winkler

Research output: Contribution to journalJournal articleResearchpeer-review

7 Citations (Scopus)

Abstract

Surface potential distributions in ultra-thin (0.8-3.9 nm) LaAlO3 layers deposited on SrTiO3 substrates are studied by Kelvin probe force microscopy. It is found that the potential distribution evolves from island-like to a homogeneous one with increasing LaAlO3 thickness. It is suggested that the observed islands are caused by a locally enhanced concentration of mobile charge carriers at the interface that is, in turn, related to non-stoichiometry of the layers with thickness below 4 unit cells. Transition to a homogeneous potential distribution with increasing LAO thickness (≥ 4 unit cells) corresponds to the formation of a quasi-2-dimensional electron gas. The results agree with a percolation model explaining the insulator-to-metal transition that occurs at the LaAlO3/SrTiO3 heterointerface.
Original languageEnglish
JournalJournal of Advanced Microscopy Research
Volume5
Issue number1
Pages (from-to)26-30
Number of pages5
ISSN2156-7573
DOIs
Publication statusPublished - Apr 2010
Externally publishedYes

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Electron gas
Surface potential
Charge carriers
Transition metals
Microscopic examination
microscopy
probes
Substrates
cells
electron gas
charge carriers
transition metals
insulators
strontium titanium oxide

Cite this

Popok, Vladimir ; Kalabukhov, Alexey ; Gunnarsson, Robert ; Lemeshko, Sergey ; Claeson, Tord ; Winkler, Dag. / Kelvin Probe Force Microscopy Study of LaAlO3/SrTiO3 Heterointerfaces. In: Journal of Advanced Microscopy Research. 2010 ; Vol. 5, No. 1. pp. 26-30.
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abstract = "Surface potential distributions in ultra-thin (0.8-3.9 nm) LaAlO3 layers deposited on SrTiO3 substrates are studied by Kelvin probe force microscopy. It is found that the potential distribution evolves from island-like to a homogeneous one with increasing LaAlO3 thickness. It is suggested that the observed islands are caused by a locally enhanced concentration of mobile charge carriers at the interface that is, in turn, related to non-stoichiometry of the layers with thickness below 4 unit cells. Transition to a homogeneous potential distribution with increasing LAO thickness (≥ 4 unit cells) corresponds to the formation of a quasi-2-dimensional electron gas. The results agree with a percolation model explaining the insulator-to-metal transition that occurs at the LaAlO3/SrTiO3 heterointerface.",
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Popok, V, Kalabukhov, A, Gunnarsson, R, Lemeshko, S, Claeson, T & Winkler, D 2010, 'Kelvin Probe Force Microscopy Study of LaAlO3/SrTiO3 Heterointerfaces', Journal of Advanced Microscopy Research, vol. 5, no. 1, pp. 26-30. https://doi.org/10.1166/jamr.2010.1020

Kelvin Probe Force Microscopy Study of LaAlO3/SrTiO3 Heterointerfaces. / Popok, Vladimir; Kalabukhov, Alexey; Gunnarsson, Robert; Lemeshko, Sergey; Claeson, Tord; Winkler, Dag.

In: Journal of Advanced Microscopy Research, Vol. 5, No. 1, 04.2010, p. 26-30.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Kelvin Probe Force Microscopy Study of LaAlO3/SrTiO3 Heterointerfaces

AU - Popok, Vladimir

AU - Kalabukhov, Alexey

AU - Gunnarsson, Robert

AU - Lemeshko, Sergey

AU - Claeson, Tord

AU - Winkler, Dag

PY - 2010/4

Y1 - 2010/4

N2 - Surface potential distributions in ultra-thin (0.8-3.9 nm) LaAlO3 layers deposited on SrTiO3 substrates are studied by Kelvin probe force microscopy. It is found that the potential distribution evolves from island-like to a homogeneous one with increasing LaAlO3 thickness. It is suggested that the observed islands are caused by a locally enhanced concentration of mobile charge carriers at the interface that is, in turn, related to non-stoichiometry of the layers with thickness below 4 unit cells. Transition to a homogeneous potential distribution with increasing LAO thickness (≥ 4 unit cells) corresponds to the formation of a quasi-2-dimensional electron gas. The results agree with a percolation model explaining the insulator-to-metal transition that occurs at the LaAlO3/SrTiO3 heterointerface.

AB - Surface potential distributions in ultra-thin (0.8-3.9 nm) LaAlO3 layers deposited on SrTiO3 substrates are studied by Kelvin probe force microscopy. It is found that the potential distribution evolves from island-like to a homogeneous one with increasing LaAlO3 thickness. It is suggested that the observed islands are caused by a locally enhanced concentration of mobile charge carriers at the interface that is, in turn, related to non-stoichiometry of the layers with thickness below 4 unit cells. Transition to a homogeneous potential distribution with increasing LAO thickness (≥ 4 unit cells) corresponds to the formation of a quasi-2-dimensional electron gas. The results agree with a percolation model explaining the insulator-to-metal transition that occurs at the LaAlO3/SrTiO3 heterointerface.

U2 - 10.1166/jamr.2010.1020

DO - 10.1166/jamr.2010.1020

M3 - Journal article

VL - 5

SP - 26

EP - 30

JO - Journal of Advanced Microscopy Research

JF - Journal of Advanced Microscopy Research

SN - 2156-7573

IS - 1

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