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Synthetic investigations in borates, borate germanates, gallium oxonitrides, and intermetallic phases at extreme conditions [Elektronische Ressource] / Gunter Heymann

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Dissertation zur Erlangung des Doktorgrades der Fakultät für Chemie und Pharmazie der Ludwig-Maximilians-Universität München Synthetic Investigations in Borates, Borate Germanates, Gallium Oxonitrides, and Intermetallic Phases at Extreme Conditions Dipl.-Chem. Gunter Heymann aus Wolfratshausen 2007 Erklärung Diese Dissertation wurde im Sinne von § 13 Abs. 3 bzw. 4 der Promotionsordnung vom 29. Januar 1998 von Herrn Priv.-Doz. Dr. H. Huppertz betreut. Ehrenwörtliche Versicherung Diese Dissertation wurde selbständig, ohne unerlaubte Hilfe erarbeitet. München, den 24.06.2006 Gunter Heymann Dissertation eingereicht am 25.06.2007 1. Gutachter: Priv.-Doz. Dr. H. Huppertz 2. Gutachter: Prof. Dr. R. Pöttgen Mündliche Prüfung am 26.07.2007 To my parents Acknowledgements First of all, I would like to express my gratitude to PD Dr. H. Huppertz for giv-ing me the opportunity to work in his group, for the freedom of research paired with continuous advertence and support, as well as for his stimulating enthusiasm. Thanks a lot for the fine and interesting COST meetings, where I was allowed to be present. Special thanks go to Prof. Dr. W. Schnick for the excellent research conditions, the unhesitant acceptance in his group, and for support in all chemical questions. I am indebted to Prof. Dr. R.

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Published 01 January 2007
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Dissertation zur Erlangung des Doktorgrades
der Fakultät für Chemie und Pharmazie
der Ludwig-Maximilians-Universität München





Synthetic Investigations in
Borates, Borate Germanates, Gallium
Oxonitrides, and Intermetallic Phases
at Extreme Conditions









Dipl.-Chem. Gunter Heymann
aus
Wolfratshausen
2007


Erklärung

Diese Dissertation wurde im Sinne von § 13 Abs. 3 bzw. 4 der Promotionsordnung
vom 29. Januar 1998 von Herrn Priv.-Doz. Dr. H. Huppertz betreut.





Ehrenwörtliche Versicherung

Diese Dissertation wurde selbständig, ohne unerlaubte Hilfe erarbeitet.


München, den 24.06.2006




Gunter Heymann





Dissertation eingereicht am 25.06.2007

1. Gutachter: Priv.-Doz. Dr. H. Huppertz
2. Gutachter: Prof. Dr. R. Pöttgen

Mündliche Prüfung am 26.07.2007

































To my parents
Acknowledgements
First of all, I would like to express my gratitude to PD Dr. H. Huppertz for giv-
ing me the opportunity to work in his group, for the freedom of research paired with
continuous advertence and support, as well as for his stimulating enthusiasm.
Thanks a lot for the fine and interesting COST meetings, where I was allowed to be
present.
Special thanks go to Prof. Dr. W. Schnick for the excellent research conditions,
the unhesitant acceptance in his group, and for support in all chemical questions.
I am indebted to Prof. Dr. R. Pöttgen for the final corrections of this thesis and
for the excellent cooperation with his group. I would like to thank him for the fruitful
discussions, ideas, and in particular for his encyclopaedic knowledge in the field of
intermetallic phases. Thank you very much also for being co-referee of this thesis.
For the steady supply of intermetallic precursors, as well as for the close coop-
eration, starting with literature support till to the enormous staying power in tiny
single crystal picking, I would like to thank Dipl.-Chem. J. F. Riecken. I wish you the
best for your PhD thesis.
I am thankful to Prof. Dr. R. Pöttgen, Prof. Dr. J. Wintterlin, Prof. Dr. D.
Johrendt, and Prof. Dr. K. Karaghiosoff for their attendance as examiners in my viva-
voce.
My colleagues Stefanie Jakob and Christian Schmolke, as well as my ex-
colleagues Florian Stadler, Oliver Schön, and Christoph Krinninger I would like to
thank for the great years of study and that they always had an open ear for chemical
and much more important, for private questions. The time passed by much too fast.
Good luck for your future.
Special thanks go to my comrade of the laboratory D2.102 Johanna Knyrim for
the calm and concentrated working atmosphere. But I will also thank her for the
numerous funny moments, which created variety and let a day pass by very quickly.
My thank is due to the press team namely, Cordula Braun, Stefanie Hering, Dr.
Friedrich Karau, Johanna Knyrim, and Florian Pucher for their collegiality and ex-
cellent team work. I also want to keep in mind and thank the famous technicians
Stephan Landerer, Markus Kutschka, Harald Ober, and Helmut Ober of our work-
shop, as well as all HiWi’s Sandra Christian, Yvonne Floredo, Jana Friedrichs,
Stephanie Neumair, Max Pitscheider, and Theresa Soltner for preparing the count-
less assembly parts.
For carrying out innumerous measurements, as well as for their postprocess-
ing, I would like to thank Sandra Albrecht, Dr. Sascha Correll, Dr. Rolf-Dieter Hoff-
mann, Dr. Bettina Lotsch, Juliane Kechele, Thomas Miller, Christian Minke, Dr. Pe-
ter Mayer, Dr. Oliver Oeckler, Dr. Sudhindra Rayaprol, Dr. Ernst-Wilhelm Scheidt,
and Wolfgang Wünschheim.
Special thanks go to my bachelor and research students Nina Behrmann, Cor-
dula Braun, Sandra Christan, Almut Haberer, and Theresa Soltner for their excellent
work. All of you were able to contribute a special part to this thesis. Good speed for
your future.
For technical support, as well as with hardware or software problems and their
quick elimination I would like to thank Wolfgang Wünschheim.
For financial support, I would like to thank the Deutsche Forschungsgemein-
schaft (DFG, Bonn).
Last but not least, for a particularly convenient working atmosphere through-
out the last years and for all sorts of technical, scientific, and personal support, I
would like to thank my present and past colleagues Yamini Avadhut, Dr. Ulrich
Baisch, Dr. Sabine Beyer, Daniel Bichler, Cordula Braun, Dr. Sascha Correll, Stefanie
Hering, Dr. Holger Emme, Cora Hecht, Elsbeth Hermanns, Stefanie Jakob, Petra Ja-
kubcová, Dr. Friedrich Karau, Juliane Kechele, Johanna Knyrim, Robert Kraut, Dr.
Alexandra Lieb, Catrin Löhnert, Dr. Bettina Lotsch, Thomas Miller, Christian Minke,
Helen Müller, Dr. Abanti Nag, Dr. Oliver Oeckler, Sandro Pagano, Dr. Regina Pocha,
Florian Pucher, Dr. Stefan Rannabauer, Rebecca Römer, Andreas Sattler, Dr. Jörn
Schmedt auf der Günne, Christian Schmolke, Stefan Sedlmaier, Jan Sehnert, Lena
Seyfarth, Theresa Soltner, Dr. Florian Stadler, Dr. Johannes Weber, Wolfgang
Wünschheim, and Martin Zeuner.
Above all, I am indebted to my parents and my brother, who continuously sup-
ported me and made a carefree study possible. Thank you very much for the en-
couragement of all of my ideas and plans.































„Die Wissenschaft besteht nur aus Irrtümern. Allerdings diese
muß man begehen. Es sind die Schritte zur Wahrheit.“
(Jules Verne)
Contents
1 Introduction 1
2 Experimental Methods 9
2.1 Precursor Preparation ........................................................................... 9
2.2 Multianvil High-Pressure Equipment .................................................. 10
2.2.1 Modified Walker-Module........................................................ 10
2.2.2 The 1000 t Press ..................................................................... 13
2.2.3 Preparation of Experiments.................................................... 16
2.2.4 Pressure Calibration ............................................................... 23
2.2.5 Temperature Calibration......................................................... 25
2.2.6 Recovering the Sample........................................................... 26
2.2.7 Experimental Dangers ............................................................ 28
3 Analytical Methods 29
3.1 X-Ray Diffraction................................................................................. 29
3.1.1 X-Ray Diffraction and Crystal Structure Analysis ................... 29
3.1.2 X-Ray Powder Diffraction ....................................................... 31
3.1.3 Temperature-programmed X-Ray Powder Diffraction ............ 31
3.1.4 Single Crystal Diffraction........................................................ 32
3.1.5 Computer Programs................................................................ 32
3.2 Energy Dispersive Analyses of X-Rays ................................................ 33
3.3 Elemental Analysis .............................................................................. 34
3.4 Infrared Spectroscopy ......................................................................... 34
3.5 Magnetic and Heat Capacity Measurements....................................... 35
3.6 Lattice Energy Calculation................................................................... 36
3.7 Bond-Length Bond-Strength Calculation ............................................ 36
3.8 Calculation of the Charge Distribution ................................................ 37
3.9 Cycle-Class Spectra ............................................................................. 37
4 Experimental Section 39
4.1 Rare-Earth Borates .............................................................................. 39
4.1.1 Introduction ............................................................................ 39
4.1.2 Starting Materials ................................................................... 45
4.1.3 The Borate α-Nd B O ............................................................ 45 2 4 9
4.1.3.1 Synthesis.................................................................. 45
4.1.3.2 Crystal Structure Analysis........................................ 46 II
4.1.3.3 Crystal Structure Description................................... 50
4.1.3.4 Theoretical Calculations........................................... 53
4.1.4 The meta-Borate β-Nd(BO ) .................................................. 54 2 3
4.1.4.1 Synthesis.................................................................. 54
4.1.4.2 Crystal Structure Analysis........................................ 54
4.1.4.3 e Description................................... 57
4.1.5 The meta-Borates δ-RE(BO ) (RE = La, Ce) ........................... 60 2 3
4.1.5.1 Synthesis 60
4.1.5.2 Crystal Structure Analysis........................................ 61
4.1.5.3 e Description................................... 65
4.1.5.4 IR Spectroscopy ....................................................... 69
4.1.5.5 Thermal Behaviour................................................... 70
4.1.5.6 Theoretical Calculations........................................... 71
4.1.6 The Oxoborate Pr B O ........................................................ 73 4 10 21
4.1.6.1 Synthesis.................................................................. 73
4.1.6.2 Crystal Structure Analysis........................................ 73
4.1.6.3 e Description................................... 78
4.1.6.4 IR Spectroscopy ....................................................... 80
4.1.6.5 Thermal Behaviour................................................... 82
4.1.7 Discussion............................................................................... 83
4.2 Rare-Earth Borate Germanates............................................................ 87
4.2.1 Introduction ............................................................................ 87
4.2.2 Starting Materials ................................................................... 90
4.2.3 The Rare-Earth Borate Germanate Ce (BO ) Ge O .............. 90 6 4 2 9 22
4.2.3.1 Synthesis.................................................................. 90
4.2.3.2 Crystal Structure Analysis........................................ 91
4.2.3.3 e Description................................... 94
4.2.3.4 Thermal Behaviour................................................... 98
4.2.3.5 Theoretical Calculations........................................... 98
4.2.3.6 Conclusion ............................................................. 100
4.3 Gallium Oxonitrides........................................................................... 101
4.3.1 Introduction .......................................................................... 101
4.3.2 The Spinel Type Structure of Ga O N ........................ 102 2.81 3.57 0.43
4.3.2.1 Synthesis................................................................ 102
4.3.2.2 Analytical Methods ................................................ 103
4.3.2.3 Results and Discussion .......................................... 105