Hydrothermal Crystal Growth of Metal Borates for Optical Applications

Crystals are the heart of the development of advance technology. Their existence is the essential foundation in the electronic field and without it there would be little to no progress in a variety of industries including the military, medical, and technology fields. The discovery of a variety of new materials with unique properties has contributed significantly to the rapidly advancing solid state laser field. Progress in the crystal growth methods has allowed the growth of crystals once plagued by difficulties as well as the growth of materials that generate coherent light in spectral regions where efficient laser sources are unavailable. The collaborative progress warrants the growth of new materials for new applications in the deep UV region. This work involves the use of hydrothermal crystal growth for exploring the descriptive chemistry of various metal borate systems in which several new structures were isolated. Conventional melt-based crystal growth methods can be problematic in synthesizing metal borates due to incongruent melting as well as the typical viscous nature of the borate flux melts. This can lead to glassy products making it difficult to grow optical quality metal borate single crystals. Due to these difficulties, other synthetic methods such as hydrothermal crystal growth for these types of materials are explored. The motivation for the exploratory research of this system derives from the commercially important &beta&ndashBaB2O4 and LiB3O5. Both materials have excellent properties however; generation of coherent light below 225 nm is inefficient due to low transmittance in the deep UV region. Similarly, several other known metal borates have good optical properties but they all have limitations. For example, beryllium containing borate KBe2BO3F2 (KBBF) have been of interest in the recent years because it generates coherent light in the deep UV region; however, a problem exists with the layered structure preventing high quality crystals from forming. Hydrothermal technique has proven to be an attractive alternative crystal growth method, especially with the growth of good quality KBBF crystals. This dissertation explores the descriptive crystal chemistry of hydrated alkali and alkaline earth borate systems in an attempt to grow &beta&ndashBaB2O4 or similar analogs. In an effort to improve the thermal properties of hydrated borates, this work was also extended to systematically introduce more stable anions and oxyanions into the borate lattice. Furthermore, preliminary photoluminescence of europium doped borate and borosilicate structures give information about their optical properties and potential applications. The work with europium led to a new rich class of europium silicates and borosilicates in which several new structures were uncovered. The formation of these new materials demonstrates the versatility of the crystal chemistry of metal borates under hydrothermal conditions

Hydro­thermally synthesized α-Ba2P2O7

Single crystals of α-Ba2P2O7, dibarium diphosphate, were obtained under hydro­thermal conditions. The structure belongs to the diphosphate A 2P2O7 series with A being an alkaline earth cation. α-Ba2P2O7 crystallizes isotypically with α-Sr2P2O7. All atomic sites have site symmetry m with the exception of two O atoms which reside on general positions. Both Ba2+ cations are coordinated by nine terminal O atoms from eclipsed diphosphate P2O7 anions to form a three-dimensional network throughout the structure

Prezygotic Barriers to Hybridization in Marine Broadcast Spawners: Reproductive Timing and Mating System Variation

Sympatric assemblages of congeners with incomplete reproductive barriers offer the opportunity to study the roles that ecological and non-ecological factors play in reproductive isolation. While interspecific asynchrony in gamete release and gametic incompatibility are known prezygotic barriers to hybridization, the role of mating system variation has been emphasized in plants. Reproductive isolation between the sibling brown algal species Fucus spiralis, Fucus guiryi (selfing hermaphrodite) and Fucus vesiculosus (dioecious) was studied because they form hybrids in parapatry in the rocky intertidal zone, maintain species integrity over a broad geographic range, and have contrasting mating systems. We compared reproductive synchrony (spawning overlap) between the three species at several temporal scales (yearly/seasonal, semilunar/tidal, and hourly during single tides). Interspecific patterns of egg release were coincident at seasonal (single peak in spring to early summer) to semilunar timescales. Synthesis of available data indicated that spawning is controlled by semidiurnal tidal and daily light-dark cues, and not directly by semilunar cycles. Importantly, interspecific shifts in timing detected at the hourly scale during single tides were consistent with a partial ecological prezygotic hybridization barrier. The species displayed patterns of gamete release consistent with a power law distribution, indicating a high degree of reproductive synchrony, while the hypothesis of weaker selective constraints for synchrony in selfing versus outcrossing species was supported by observed spawning in hermaphrodites over a broader range of tidal phase than in outcrossers. Synchronous gamete release is critical to the success of external fertilization, while high-energy intertidal environments may offer only limited windows of reproductive opportunity. Within these windows, however, subtle variations in reproductive timing have evolved with the potential to form ecological barriers to hybridization

CCDC 882913: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: C.Heyward, C.McMillen, J.Kolis|2012|Inorg.Chem.|51|3956|doi:10.1021/ic202316

CCDC 882914: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.,Related Article: C.Heyward, C.McMillen, J.Kolis|2012|Inorg.Chem.|51|3956|doi:10.1021/ic202316

CCDC 970779: Experimental Crystal Structure Determination

Related Article: Carla Heyward, Colin D. McMillen, Joseph Kolis|2013|J.Solid State Chem.|203|166|doi:10.1016/j.jssc.2013.04.022,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 970781: Experimental Crystal Structure Determination

Related Article: Carla Heyward, Colin D. McMillen, Joseph Kolis|2013|J.Solid State Chem.|203|166|doi:10.1016/j.jssc.2013.04.022,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 1061669: Experimental Crystal Structure Determination

Related Article: Colin McMillen , Carla Heyward , Henry Giesber , Joseph Kolis|2011|J.Solid State Chem.|184|2966|doi:10.1016/j.jssc.2011.08.023,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 1061668: Experimental Crystal Structure Determination

Related Article: Colin McMillen , Carla Heyward , Henry Giesber , Joseph Kolis|2011|J.Solid State Chem.|184|2966|doi:10.1016/j.jssc.2011.08.023,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures

CCDC 1061667: Experimental Crystal Structure Determination

Related Article: Colin McMillen , Carla Heyward , Henry Giesber , Joseph Kolis|2011|J.Solid State Chem.|184|2966|doi:10.1016/j.jssc.2011.08.023,An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures