Crystal Chemistry, Synthesis, and Characterization of Infrared Optical Materials

1989 ◽  
Vol 152 ◽  
Author(s):  
D. O. Kipp ◽  
C. K. Lowe-Ma ◽  
T. A. Vanderah

ABSTRACTNon-oxide inorganic compounds such as sulfides, phosphides, and mixed-anion sulfidephosphides are of interest as possible infrared window materials. Our research on the solid state chemistry and structure-property relationships of these materials includes the directed synthesis of new compounds as well as the study of compounds that have been reported in the literature but which have been incompletely characterized for this application. The present work includes investigations of three ternary sulfide systems: ZnGa2S4, AIn2S4, (A = Ca,Sr,Ba), and CaY2S4. Samples were prepared in polycrystalline form and/or as crystals. New compounds were obtained in our studies of the CaIn2S4, SrIn2S4, and CaY2S4 systems. Compounds were characterized by X-ray diffraction, elemental analysis, FMR, and thermogravimetric analysis.

1990 ◽  
Vol 216 ◽  
Author(s):  
C.K. Lowe-Ma ◽  
D.O. Kipp ◽  
T.A. Vanderah

ABSTRACTSome applications for long-wavelength infrared (LWIR) windows require environmental durability and mechanical strength in addition to infrared optical transparency; i.e., the windows must simultaneously serve as optical and as structural ceramics. The requirement of optical transparency at long IR wavelengths eliminates from consideration all ceramics based on oxides and other light-anion compounds, making this a particularly difficult materials problem. The structure-property relationships and chemical rationale used to guide both the screening of known compounds and the synthesis of new compounds likely to possess the desired properties rely on factors such as atomic mass, electronic configuration, coordination number, and crystal structure type.Our research has included the directed synthesis and characterization of a number of ternary indium sulfides as well as ternary calcium yttrium sulfides. Ternary indium sulfides feature both tetrahedral and octahedral coordination of indium. The crystal structure of KInS2 and its relationship to structures observed in other systems such as AIn2S4, A = Ca,Sr,Ba, is described. The crystal structure of CaY2S4 along with studies of yttrium-doped CaS are also described. The AIn2S4 compounds are more fully described in references [1] and [2].


2013 ◽  
Vol 9 ◽  
pp. 866-876 ◽  
Author(s):  
Amaresh Mishra ◽  
Elena Mena-Osteritz ◽  
Peter Bäuerle

Pd-catalyzed Sonogashira cross-coupling reactions were used to synthesize novel π-conjugated oligothienylene-ethynylene dendrons and their corresponding terpyridine-based ligands. Their complexation with Ru(II) led to interesting novel metallodendrimers with rich spectroscopic properties. All new compounds were fully characterized by 1H and 13C NMR, as well as MALDI–TOF mass spectra. Density functional theory (DFT) calculations performed on these complexes gave more insight into the molecular orbital distributions. Photophysical and electrochemical studies were carried out in order to elucidate structure–property relationships and the effect of the dendritic structure on the metal complexes. Photophysical studies of the complexes revealed broad absorption spectra covering from 250 to 600 nm and high molar extinction coefficients. The MLCT emission of these complexes were significantly red-shifted (up to 115 nm) compared to the parent [Ru(tpy)2]2+ complex.


2020 ◽  
Vol 235 (6-7) ◽  
pp. 213-223
Author(s):  
Hilke Petersen ◽  
Lars Robben ◽  
Thorsten M. Gesing

AbstractThe temperature-dependent structure-property relationships of the aluminosilicate perrhenate sodalite |Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD) were analysed via powder X-ray diffraction (PXRD), Raman spectroscopy and heat capacity measurements. ReO4-SOD shows two phase transitions in the investigated temperature range (13 K < T < 1480 K). The first one at 218.6(1) K is correlated to the transition of dynamically ordered $P\overline{4}3n$ (> 218.6(1 K) to a statically disordered (<218.6(1) K) SOD template in $P\overline{4}3n$. The loss of the dynamics of the template anion during cooling causes an increase of disorder, indicated by an unusual intensity decrease of the 011-reflection and an increase of the Re-O2 bond length with decreasing temperature. Additionally, Raman spectroscopy shows a distortion of the ReO4 anion. Upon heating the thermal expansion of the sodalite cage originated in the tilt-mechanism causes the second phase transition at 442(1) K resulting in a symmetry-increase from $P\overline{4}3n$ to $Pm\overline{3}n$, the structure with the sodalites full framework expansion. Noteworthy is the high decomposition temperature of 1320(10) K.


2017 ◽  
Vol 46 (25) ◽  
pp. 8304-8305
Author(s):  
Dalia M. Abdel Basset ◽  
Suresh Mulmi ◽  
Mohammed S. El-Bana ◽  
Suzan S. Fouad ◽  
Venkataraman Thangadurai

Correction for ‘Synthesis and characterization of novel Li-stuffed garnet-like Li5+2xLa3Ta2−xGdxO12 (0 ≤ x ≤ 0.55): structure–property relationships’ by Dalia M. Abdel Basset, et al., Dalton Trans., 2017, 46, 933–946.


2004 ◽  
Vol 844 ◽  
Author(s):  
David J. Scurr ◽  
Stephen J. Eichhorn

ABSTRACTThis study uses various characterisation techniques on the razor shell (Ensis siliqua), to relate the shell's microstructure to its mechanical properties. Scanning electron microscopy (SEM) has shown that the outer and inner regions of the shell are composed of simple and complex crossed lamellar microstructures respectively. These layers are interspersed by prismatic layers of a completely different crystallographic orientation. Nanoindentation and microhardness measurements have shown that the structure is anisotropic, and Raman band shifts have been observed within these indented/deformed areas of shell, showing that the microstructure deforms rather than generating surface damage. The use of energy variable synchrotron X-ray diffraction has shown that the calcium carbonate crystals of the shell are preferentially orientated as a function of depth and that opposing residual stresses exist at the outer and inner regions of the shell. This study has analysed several microstructural features of the shell and provided an insight into how they prevent failure of the material.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olha Zhak ◽  
Oksana Karychort ◽  
Volodymyr Babizhetskyy ◽  
Chong Zheng

Abstract The title compound was prepared from the pure elements by sintering. The crystal structure was investigated by means of powder X-ray diffraction data. Ho5Pd19P12 exhibits the hexagonal Ho5Ni19P12-type structure with space group P 6 ‾ 2 m $P&#x203e;{6}2m$ , a = 13.1342(2), c = 3.9839(1) Å, R I = 0.060, R p = 0.080. The crystal structure can be described as a combination of two types of the structural units, [HoPd6P3] and [Ho3Pd10P6], respectively, mutually displaced by 1/2 along the crystallographic c axis. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The results of the quantum chemical calculations indicate that the material features metallic bonding between Ho and Pd and covalent bonding between Pd and P.


1989 ◽  
Vol 156 ◽  
Author(s):  
Aaron Wold ◽  
Kirby Dwight

ABSTRACTThe structure-property relationships of several conducting transition metal oxides, as well as their preparative methods, are presented in this paper. The importance of preparing homogeneous phases with precisely known stoichiometry is emphasized. A comparison is also made of the various techniques used to prepare both polycrystalline and single crystal samples. For transition metal oxides, the metallic properties are discussed either in terms of metal-metal distances which are short enough to result in metallic behavior, or in terms of the formation of a П* conduction band resulting from covalent metal-oxygen interactions. Metallic behavior is observed when the conduction bands are populated with either electrons or holes. The concentration of these carriers can be affected by either cation or anion substitutions. The discussion in this presentation will be limited to the elements Re, Ti, V, Cr, Mo, and Cu.


2014 ◽  
Vol 1673 ◽  
Author(s):  
Jason E. Bara ◽  
Matthew S. Shannon ◽  
W. Jeffrey Horne ◽  
John W. Whitley ◽  
Haining Liu ◽  
...  

ABSTRACTImidazoles present a tunable, versatile and economical platform for the development of novel liquid solvents and polymer membranes for CO2 capture. An overview of our studies in this area is presented, with emphasis on characterization of structure-property relationships in imidazole-based materials through both experimental and computational studies. To this end, a growing library of systematically varied imidazole compounds has been synthesized using only commercial available starting materials and straightforward reactions. Using this library of compounds, we have sought to understand and develop predictive models for thermophysical properties relating to process design, including: density, viscosity, vapor pressure, pKa and CO2 absorption capacity. Furthermore, we have discovered that imidazoles are stable in the presence of SO2 and can form reversible 1:1 adducts, which can be beneficial as SO2 is typically present at ppm levels alongside CO2 in flue gas from coal-fired power plants.


2002 ◽  
Vol 75 (5) ◽  
pp. 853-864 ◽  
Author(s):  
Judit E. Puskas ◽  
Christophe Paulo ◽  
Volker Altstädt

Abstract Structure-property relationships were investigated in hyperbranched polyisobutylenes, in comparison with commercial linear butyl rubber. The gel-free, soluble hyperbranched polyisobutylenes, synthesized by living carbocationic polymerization, had molecular weights, Mw≈400,000 to 1,000,000 g/mol, molecular weight distributions, MWD ≈1.2 to 2.6, and branching frequencies, BR ≈ 4 to 60. The mechanical and viscoelastic characterization of these polymers revealed interesting properties, including the characteristics of crosslinked rubbers.


2012 ◽  
Vol 1376 ◽  
Author(s):  
J.C. Pérez-Reyes ◽  
G. Carbajal-De la Torre ◽  
M. A. Espinosa-Medina ◽  
L. A. Ibarra-Bracamontes ◽  
M. Villagómez-Galindo ◽  
...  

ABSTRACTOsteoarthritis is a very complex illness of the joints that affects cartilage and subcondral bone. At the last years, researching has been focused in the development and characterization of composite materials, evaluating their structural properties. Some o those composite materials are constituted by organic and inorganic compounds forming hybrids. These materials can improve their properties due to the interaction of reinforcement hard particles in the polymeric matrix. The interest on the composite biomaterials has been increased on the biomedical applications such as tissue regenerating based in synthetic polymers with biodegradable and biocompatible properties whose can be reinforced by calcium phosphates. In this sense, hydroxyapatite [Ca10(PO4)6(OH)2] is often used for biological implants due its mineral phase similitude with bone microstructure and tissue compatibility. Similarly, polylactic acid (PLA) is a used polymer for implant applications due physicochemical and biocompatibility properties, and short degradation time also. In order to obtain a composite that can be used as a regenerating material on the osteoarthritis problem, in this work a (90/10 wt.%) polylactic/hydroxyapatite hybrid composite was produced by chemical synthesis and characterized by X-ray diffraction, SEM, FT-IR and TGA/DSC techniques.


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