Liquid-delivery metal-organic chemical vapour deposition of perovskites and perovskite-like compounds [Elektronische Ressource] / Rasuole Lukose. Gutachter: Erhard Kemnitz ; Roberto Fornari ; Anjana Devi

Rasuole Lukose

Sujets

• Physik

Informations

• Publié par: humboldt-universitat_zu_berlin
• Publié le: 01 janvier 2011
• Nombre de lectures: 51
• Langue: English
• Poids de l'ouvrage: 12 Mo

Extrait

Chemie

Dissertation
Liquid-Delivery Metal-Organic Chemical
Vapour Deposition of Perovskites and
Perovskite-Like Compounds


zur Erlangung des akademischen Grades
doctor rerum naturalium
(Dr. rer. nat.)

Mathematisch-Naturwissenschaftlichen Fakultät I
der Humboldt-Universität zu Berlin

Frau M. Sc. Rasuole Lukose

Dekan: Prof. Dr. Andreas Herrmann
Gutachter: 1. Prof. Dr. Erhard Kemnitz
2. Prof. Dr. Roberto Fornari
3. Prof. Dr. Anjana Devi

eingereicht: 26.07.2010

Datum der Promotion: 09.09.2010
Selbstständigkeitserklärung



Hiermit erkläre ich, das ich die vorliegende Dissertation selbständig angefertigt habe
und nur die angegebenen Quellen und Hilfsmittel verwendet habe.







(Datum, Ort) Rasuole Lukose



















1 Acknowledgments

I wish to express my sincere gratitude to my research supervisor Prof. Dr. Roberto
Fornari, for providing me the opportunity to make my PhD at the Leibniz-Institute for Crystal
Growth, for his support throughout this work and his helpful suggestions in reviewing this
thesis.
My special thanks go to Prof. Dr. Erhard Kemnitz at Humboldt University for accepting
my candidature as a PhD student and for the assistance at the University.
I equally express my gratitude to the leader of the oxide layers group, Dr. Jutta
Schwarzkopf, who directly supervised this work. I am thankful for the support in every aspect
of the experimental work, comprehensive and useful discussions.
I am also very grateful to my colleague Dr. Günter Wagner not only for the helpful
conversations in scientific field but as well as for his help in daily life. I would like to express
my gratitude to group colleagues, Sebastian Markschies and Dr. Saud Bin Anooz for the nice
working atmosphere and for the fact that I could always rely on their assistance.
I would like to express my gratitude to Jr. Prof. Dr. Anjana Devi for the effective
collaboration in the field of metal-organic precursors that were applied in this particular work.
In this context, I would like to thank also all the PhD students of her group, especially Daniela
Beckerman and Ke Xu, for the thermoanalytic measurements of metal-organic precursors.
I would like to thank sincerely to my colleagues at IKZ, especially PD Dr. habil. Martin
Schmidbauer for his help and advices concerning High Resolution X-ray Diffraction
measurements and Albert Kwasniewski for performing these measurements. I am grateful to
Dr. Klaus Irmscher for the discussions on electrical results, Mike Pietsch for performing these
measurements and Dr. Martin Albrecht for the support in characterization with Scanning
Electron Microscopy and Transmission Electron Microscopy. In this context, I would like to
thank Dr. habil. Detlef Klimm and Steffen Ganschow for their help performing some
measurements of the metal-organic precursors. My special thanks go to Dr. Reinhard Uecker
for the supply of the substrates and useful discussions about oxide materials.
I also want to thank the colleagues from the Department of Physics in Humboldt
University, namely Jens Lienemann, Dr. Marco Busch and Prof. Dr. Helmut Winter for the
fruitful collaboration and AES measurements.
Additionally, I would like to thank Dr. Andrea Harrer, Carsten Hartmann, Dr. Tobias
Schulz, Dr. Daniela Gogova for the friendly and encouraging atmosphere at work and also
outside the Institute.
2 My specials thanks go to my colleagues at Faculty of Chemistry in Vilnius University,
especially Dr. Valentina Plausinaitiene for the scientific discussions and support.
Last but not the least; I express huge thanks to my family: my husband, my mother and
my sister for their support, encouragement and trust in me during all these study years.
































3 Abstract

Perovskites and perovskite-like materials are actually of great interest since they offer a
wide range of structural and physical properties giving the opportunity to employ these
materials for different applications.
Liquid-Delivery Metal Organic Chemical Vapour deposition (LD-MOCVD) was chosen
due to the easy composition control for ternary oxides, high uniformity and good conformal
step coverage. Additionally, it allows growing the films, containing elements, for which only
solid or low vapour pressure precursors, having mainly thermal stability problems over long
heating periods, are available.
The purpose of this work was to grow SrRuO , Bi Ti O and (Na, Bi) Ti O films by 3 4 3 12 4 3 12
LD-MOCVD and to investigate the influence of the deposition conditions on the properties of
the films. Additionally, the effect of the strain due to the lattice mismatch between substrates
and films on the physical properties of the films was also investigated.
SrRuO films were grown on stepped SrTiO (001), NdGaO (110) and DyScO (110) 3 3 3 3
substrates, which were prepared under different conditions by changing the annealing time
and atmosphere. The termination of the substrates was measured by surface sensitive proton-
induced Auger Electron Spectroscopy (p-AES) technique.
Another systematic study of the relation between epitaxial strain and Curie temperature
of thin SrRuO (100) films was performed by using substrates with different lattice constants. 3
The observed Curie temperature decreased with compressive and increased with tensile strain.
Thin films of Bi Ti O as well as (Na, Bi) Ti O were successfully deposited. In order 4 3 12 4 3 12
to grow stoichiometric and epitaxial Bi Ti O (001) films, Bi excess in the precursor solution 4 3 12
was necessary, due to the volatility of Bi. Substitution of Bi with Na in Bi Ti O was 4 3 12
achieved for the first time for the films deposited by LD-MOCVD.

Perovskites, LD-MOCVD, oxide substrates, thin films, strain.







4 Zusammenfassung

Perowskite und Perowskit-artige Materialien sind von großem Interesse, da sie eine
Vielzahl von strukturellen und physikalischen Eigenschaften haben, welche die Möglichkeit
bieten, sie für unterschiedliche Anwendungen einzusetzen.
Die Methode der Liquid-Delivery Metal Organic Chemical Vapour Deposition (LD-
MOCVD) wurde gewählt, da sie eine gute Kontrolle über die Zusammensetzung ternärer
Oxide und eine hohe Homogenität der Filme ermöglicht. Darüber hinaus können mit dieser
Methode Filme hergestellt werden, die aus Elementen bestehen, für welche nur feste
Precursor oder welche mit niedrigem Dampfdruck zur Verfügung stehen.
Ziel dieser Arbeit war es, mit Hilfe der LD-MOCVD Filme aus SrRuO , Bi Ti O und 3 4 3 12
(Na,Bi) Ti O abzuscheiden und den Einfluss der Wachstumsbedingungen auf die 4 3 12
Eigenschaften der Filme zu untersuchen. Zusätzlich wurde die Wirkung der Verspannung, die
durch die Gitterfehlanpassung zwischen Substrat und Film entsteht, auf die physikalischen
Eigenschaften der Schichten untersucht.
SrRuO Filme wurden auf gestuften SrTiO (001), NdGaO (110) und DyScO (110) 3 3 3 3
Substraten gewachsen, deren Oberflächenterminierung durch oberflächensensitive Proton-
induzierte Auger-Elektronen-Spektroskopie (AES) bestimmt wurde. Die Substrate wurden
unter verschiedenen Bedingungen durch Änderung der Temperdauer und -atmosphäre
präpariert.
Die systematische Untersuchung der Beziehung zwischen Verspannung und Curie-
Temperatur von dünnen SrRuO (100) Filmen erfolgte unter Verwendung von Substraten mit 3
unterschiedlichen Gitterkonstanten. Die beobachtete Curie-Temperatur sank mit erhöhter
kompressiver Verspannung und nahm mit erhöhter tensiler Verspannung zu.
Um stöchiometrische und epitaktische Bi Ti O (001) Filme zu wachsen, war aufgrund 4 3 12
der Flüchtigkeit des Bismuts ein Bi Überschuss in der Precursor-Lösung notwendig. Die
Substitution von Bi durch Na in Bi Ti O wurde zum ersten Mal in LD-MOCVD-Filmen 4 3 12
erreicht.


Perowskite, LD-MOCVD, oxidische Substrate, dünne Filme, Verspannung.







5 Table of contents
Selbstständigkeitserklärung .........................................................................................1
Acknowledgments..........................................................................................................2
Abstract ..........................................................................................................................4
Zusammenfassung .........................................................................................................5
Table of contents............................................................................................................6
List of Abbreviations.....................................................................................................8
Introduction ......