(Na,K) Aluminosilicate Hollandites [Elektronische Ressource] : structures, crystal chemistry, and high-pressure behaviour / vorgelegt von Jun Liu

Jun Liu

Informations

• Publié par: universitat_bayreuth
• Publié le: 01 janvier 2007
• Nombre de lectures: 15
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

“(Na,K) Aluminosilicate Hollandites: Structures, Crystal
Chemistry, and High-pressure Behaviour”






Von der Fakultät für Biologie, Chemie und Geowissenschaften der Universität Bayreuth




Zur Erlangung des akademischen Grades
Doctor der Naturwissenschaften
-Dr. rer. nat.-




genehmigte Dissertation




vorgelegt von

Jun Liu












Bayreuth, 2007




Table of contents _
Table of contents

Summary 1

Zusammenfassung 5

1. Introduction 10
1.1The importance of potassium and sodium in the deep Earth……………..…………10
1.1.1 Potassium-40 and the Earth’s core………………………………………..….11
1.1.2 Importance of potassium and sodium in the lower mantle…….…………….11
1.2 K-Na aluminosilicate hollandite: possible host mineral for K and Na in the Earth’s
mantle……………………………………………………………………….………………...13
1.2.1 The hollandite structure…………………………………….………………..13
1.2.2 The (K,Na)AlSi O hollandite solid solution…………………………….…..15 3 8
1.2.3 The experimental stability field of (K,Na)AlSi O hollandite…………….…16 3 8
1.2.4 The natural occurrence of (K, Na) aluminosilicate hollandite: hollandite in
meteorites……………………………………………………………………………………...18
1.3 Previous study……………………………………………………………….……..19
1.3.1 High-pressure study of the KAlSi O hollandite…………………………….19 3 8
1.3.2 Study of the KAlSi O - NaAlSi O hollandite solid solution……………….21 3 8 3 8
1.4 Aim of this research……………………………………………………….………23

2. Experimental techniques and sample characterization 24
2.1 Samples……………………………………………………………………………24
2.1.1 Starting materials……………………………………………………………24
2.1.2 Multi anvil technique………………………………………………………..26
2.1.3. Characterisation of the run products………………………………………..30
2.1.3.1 Chemical analysis……………………………………….………….30
2.1.3.2 X-ray powder diffraction…………………………………………...32
2.1.3.3 X-ray single-crystal diffraction………………………….………….33
2.2 High-pressure and high-temperature techniques………………………...……….36
Table of contents _
2.2.1 Diamond anvil cells…………………………………………..………….…36
2.2.2 Raman experiments………………………………………………………...39
2.2.3 High pressure X-ray powder diffraction experiments………….…………..40
2.2.3.1 High-pressure X-ray experiments at the BGI……………………...40
2.2.3.2 Synchrotron radiation X-ray powder diffraction…………………..41

3. Results 43
3.1 (K,Na)AlSi O hollandite solid solution………………...………..………..………43 3 8
3.1.1 Chemical composition……………………………………………………...43
3.1.2 X-ray powder diffraction…………………………………………………...46
3.1.3 Raman spectra………………………………………………………………50
3.1.4 Crystal structure…………………………………………………………….53
3.2 High pressure and high temperature behaviour of LiF……………………………57
3.3 High pressure behaviour of Na K AlSi O hollandite in helium as pressure 2 8 3 8
transmitting medium…………………………………………………………………………..58
3.3.1 Unit-cell lattice parameter determination at room T ………………………58
3.3.2 Equation of state…………………………………………………………...63
3.3.2.1 The f-F plot……………………………………………………..65
3.3.3 Spontaneous strain:…………………...…………………………………...67
3.4 High pressure behaviour of K Na AlSi O hollandite in helium as pressure 0.5 0.5 3 8
transmitting medium ………………………………………………………………………….72
3.4.1. The equation of state……………………………………………………...73
3.5 High pressure behaviour of K Na AlSi O hollandite in lithium fluoride as 0.8 0.2 3 8
pressure transmitting medium ………………………..………………………...……………..73
3.5.1 The Equation of state……………………………………………………...74
3.6 High pressure behaviour of K Na AlSi O hollandite in lithium fluoride as 0.6 0.4 3 8
pressure transmitting medium …………………………………………………………….…..74
3.6.1 The Equation of state……………………………………………………..76
3.7 High pressure high-temperature behaviour of K Na AlSi O hollandite in lithium 0.5 0.5 3 8
fluoride as pressure transmitting medium…...………………………………………………...79
3.8 High pressure Raman experiments………………………………………...……..84
Table of contents _
3.8.1 High pressure Raman experiments of KAlSi O hollandite in argon as 3 8
pressure transmitting medium……………………………………………………….………84
3.8.2 High pressure Raman experiment of K Na AlSiO hollandite in 0.6 0.4 8
lithium fluoride as pressure transmitting medium ……………………………….………….89

4. Discussion 93
4.1 The (Na,K)AlSi O hollandite solid solution………………….……………….93 3 8
4.1.1 Solid solution behaviour………………………………….…………..93
4.1.2 The NaAlSi O hollandite………………………………….…………95 3 8
4.1.3 The symmetry in (K,Na)AlSi O hollandite: tetragonal vs. 3 8
monoclini…………………………………………………………………………….………..96
4. 2 High pressure and high temperature behaviour of (Na, K) h….…….………...102
4.2.2 The Spontaneous strain behaviour of the tetragonal to monoclinic high-
pressure phase transition in hollandite……………………………………………………….103
4.2.2.1. Spontaneous strain behaviour under hydrostatic
condition……………………………………………………………………………………..103
4.2.2.2. Spontaneous strain behaviour in lithium fluoride………….104

5. Conclusions 107

References 109

Appendix 127
Appendix 1: Indexed peaks in lattice parameter refinement………………………127
Appendix 2: Rietveld Refinement Patterns from high pressure experiment of
K Na AlSi O hollandite in helium……………………………………………………….136 0.8 0.2 3 8

Erklärung 148





Acknowledgements

There are many people I wish to thank for their help and support. First of all, I want to thank Tiziana
Boffa-Ballaran, the person I owe most to at Bayerisches Geoinstitut. I am so grateful to her, for all her
help, suggestions and support, which made completion of this work possible. Tiziana, thank you so
much! Both of my supervisers Tiziana and Leonid Dubrovinsky have been very supportive and very
patient with me, and have given me the most help. I thank Leonid for all the helps, great suggestions,
and all the work you have put into being my superviser!

I thank Dan Frost for all his help in multi-anvil lab, and for giving me important suggestions and helps
during my study. Thank you Florian Heidelbach for the help and effort you’ve done for my thesis.
Thank you Fritz Seifert for all the kind help and support you’ve given me. Thank you Detlef Krausse
and Anke Potzel for giving me lots of help in the probe lab, and Detlef also fixed all my computer
problems. Thank you Stefan Keyssner for the help and making me feel at home here. Thank you
Innokenty Kantor and Alexander Kurnosov for all your helps in Raman labs. I thank Ahmed El Goresy
for all his help and suggestions. Thank you Nobuyoshi Miyajima for all the help. I thank Gerd Steinle-
Neumann for all the help and knowledge I learned here!

I am also grateful to Andreas Audétat, Xin Nie, and Zhengning Tang for all