Clemson University TigerPrints All Dissertations Dissertations 5-2007 Hydrothermal Crystal Growth of Oxides for Optical Applications Colin Mcmillen Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_dissertations Part of the Inorganic Chemistry Commons Recommended Citation Mcmillen, Colin, "Hydrothermal Crystal Growth of Oxides for Optical Applications" (2007). All Dissertations. 56. https://tigerprints.clemson.edu/all_dissertations/56 This Dissertation is brought to you for free and open access by the Dissertations at TigerPrints. It has been accepted for inclusion in All Dissertations by an authorized administrator of TigerPrints. For more information, please contact [email protected]. HYDROTHERMAL CRYSTAL GROWTH OF OXIDES FOR OPTICAL APPLICATIONS A Dissertation Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Chemistry by Colin David McMillen May 2007 Accepted by: Dr. Joseph W. Kolis, Committee Chair Dr. Shiou-Jyh Hwu Dr. William Pennington Dr. Richard Warner ABSTRACT The manipulation of light has proven to be an integral part of today’s technology-based society. In particular, there is great interest in obtaining coherent radiation in all regions of the optical spectrum to advance technology in military, medical, industrial, scientific and consumer fields. Exploring new crystal growth techniques as well as the growth of new optical materials is critical in the advancement of solid state optics. Surprisingly, the academic world devotes little attention to the growth of large crystals. This shortcoming has left gaps in the optical spectrum inaccessible by solid state devices. This dissertation explores the hydrothermal crystal growth of materials that could fill two such gaps. The first gap exists in the deep-UV region, particularly below 200 nm. Some materials such as LiB3O5 and β-BaB2O4 can generate coherent light at wavelengths as low as 205 nm. The growth of these materials was explored to investigate the feasibility of the hydrothermal method as a new technique for growing these crystals. Particular attention was paid to the descriptive chemistry surrounding these systems, and several novel structures were elucidated. The study was also extended to the growth of materials that could be used for the generation of coherent light as low as 155 nm. Novel synthetic schemes for Sr2Be2B2O7 and KBe2BO3F2 were developed and the growth of large crystals was explored. An extensive study of the structures, properties and crystal growth of related compounds, RbBe2BO3F2 and CsBe2BO3F2, was also undertaken. Optimization of a number of parameters within this family of compounds led to the hydrothermal growth of large, high quality single crystal at rates suitable for large-scale growth. The second gap in technology is in the area of high average power solid state lasers emitting in the 1 μm and eye-safe (>1.5 μm) regions. A hydrothermal technique was developed to grow high quality crystals of Sc2O3 and Sc2O3 doped with suitable lanthanide activator ions. Preliminary spectroscopic studies were performed and large crystals were again grown at rates suitable for commercial production. The synthesis of ultra-high purity Ln2O3 (Ln = Sc, Y, La-Lu) nanoparticles was also explored to advance the development of ceramic-based solid state lasers. Crystal growth is a complex task involving a great number of intricacies that must be understood and balanced. This dissertation has advanced the art and science of growing crystals, and documented the development of large, high quality crystals of advanced optical materials The materials and hydrothermal crystal growth techniques developed over the course of this work represent important progress toward controlling the optical spectrum. iv DEDICATION This work is dedicated to the glory of God, for with God, all things are possible (Matthew 19:26). ACKNOWLEDGEMENTS I wish to thank my advisor, Professor Joe Kolis, for his guidance throughout this work and for providing me with all the resources necessary to be successful in this effort. I am especially grateful for the freedom to put my own twist on this research and take it in whichever direction I was so inclined. I offer special thanks to Dr. Bill Pennington and Dr. Don VanDerveer for teaching me some nuances of crystallography and offering many helpful discussions. I am also appreciative of the collaboration I have enjoyed with Dr. John Ballato that has presented a number of new directions for this research. Additionally, I thank Dr. P. Shiv Halasyamani and Dr. Kang Minh-Ok for providing the equipment and training necessary to obtain SHG data on a number of compounds presented within these chapters. Taina Franco, Baris Kokuoz and Matthew Dejneka have also generously contributed their time and effort toward research included here. I wish to express my appreciation to those members of the Kolis Research Group with whom I have spent the most time in the trenches including Dr. Ed Abbott, Dr. Alfred Forbes, Evy Colon-Garcia, Jia Hu, Matthew Mann and Seth Stepleton. I am particularly grateful for my parents Charles and Cynthia, who have been loving and supportive in my upbringing and throughout my education. Most of all, I thank my wonderful wife Laura, who has been unwavering in her love, patience and support since the first day of my graduate studies. Your contribution to my life is far beyond what these pages can hold. TABLE OF CONTENTS Page TITLE PAGE ........................................................................................... i ABSTRACT ................................................................................................ iii DEDICATION ............................................................................................ v ACKNOWLEDGEMENTS ..................................................................... vii LIST OF FIGURES .................................................................................... xiii LIST OF TABLES ...................................................................................... xvii CHAPTER 1 INTRODUCTION .......................................................................... 1 Crystal Growth as Chemistry and Art ....................................... 1 Crystal Growth and Technological Advancement .................... 2 Current Interests in Crystal Growth and Solid-State Lasers ............................................................... 4 Traditional Crystal Growth Techniques.................................... 9 Hydrothermal Crystal Growth .................................................. 14 Perspectives – Past and Present ................................................ 17 References ................................................................................. 20 2 EXPERIMENTAL TECHNIQUE ................................................. 23 Hydrothermal Synthesis in Floating Liners .............................. 23 Relative Solubility Studies ........................................................ 27 Transport Growth ...................................................................... 30 Powder X-Ray Diffraction ........................................................ 34 Single Crystal X-Ray Diffraction ............................................. 35 Thermal Analysis ...................................................................... 36 Electron Microscopy and Elemental Analysis .......................... 37 Vibrational Spectroscopy .......................................................... 37 UV-Vis-NIR Spectroscopy ....................................................... 38 Lanthanide Ion Spectroscopy .................................................... 39 Non Linear Optical Susceptibility Measurements .................... 39 References ................................................................................. 43 Table of Contents (Continued) Page 3 HYDROTHERMAL SURVEY OF LITHIUM BORATES .............................................................. 45 Introduction ............................................................................... 45 Hydrothermal Phase Stability of Lithium Borates .................... 49 Structural Comparison of Tetragonal and MonoclinicLithium Metaborate .......................................... 53 Solubility Study of γ-LiBO2 ...................................................... 58 Optimized Transport Growth of γ-LiBO2 ................................. 61 Optical and Non Linear Optical Properties of γ-LiBO2 ........................................................................... 64 Conclusions .............................................................................. 67 References ................................................................................. 69 4 HYDROTHERMAL CHEMISTRY OF BARIUM BORATES .............................................................. 71 Introduction ............................................................................... 71 Hydrothermal Reactions of BBO .............................................. 75 Direct Synthesis of Hydrated Alkaline Earth Metal Borates ............................................................ 79 The Crystal Structure of Ba2B5O9(OH) .................................... 85 The Crystal Structure of Ba3B12O20(OH)2 ................................ 95 The Crystal Structure of Ba2B7O12(OH) ................................... 101 The Crystal Structure of Ba3B6O11(OH)2 .................................