Synthesis of Metal Sulfide Powders From Organometallics

1986 ◽  
Vol 73 ◽  
Author(s):  
Curtis E. Johnson ◽  
Deborah K. Hickey ◽  
Daniel C. Harris
Keyword(s):  
Metal Sulfide ◽  
Organometallic Complexes ◽  
X Ray Diffraction ◽  
Organometallic Reagents ◽  
X Ray ◽  
Optical Ceramics ◽  
Low Temperature Preparation ◽  
Temperature Electron ◽  
Organozinc Reagents ◽  
Temperature Preparation

ABSTRACTOrganometallic reagents have been examined for the low-temperature preparation of metal sulfide powders which are desired as precursors to optical ceramics. The general approach is typified by the reaction of diethylzinc with hydrogen sulfide in toluene solution at room temperature. Electron microscopy shows that the white ZnS product consists of aggregates of ≤ 0.1 μm particles. The product is further characterized as predominantly cubic zinc sulfide (X-ray diffraction) which contains some residual hydrocarbon. Various organozinc reagents and experimental procedures have been tried in order to optimize the reaction. The reaction has also been extended to organometallic complexes of Al and Mg, and also to a ternary system, ZnAl2 S4

Low Temperature Preparation of y‐bA‐cU‐0 Films by Omcvd

1989 ◽  
Vol 169 ◽  
Author(s):  
Taiji Tsuruoka ◽  
Ryodo Kawasaki ◽  
Hitoshi Abe ◽  
Susumu Shibata
Keyword(s):  
Low Temperature ◽  
Deposition Rate ◽  
X Ray Diffraction ◽  
Axis Orientation ◽  
X Ray ◽  
Low Temperature Preparation ◽  
Zero Resistance ◽  
Diffraction Patterns ◽  
Temperature Preparation

AbstractBy using N2O for oxygen source, Y‐Ba‐Cu‐O films prepared at 650” C on the SrTiO3 substrates showed zero resistance at 79K. The deposition rate of Y‐Ba‐Cu‐0 films on MgO(l00) substrates by using N2O gas was nearly half of that using 02 gas. X‐ray diffraction patterns of Y‐Ba‐Cu‐0 films grown on SrTiO3(100) and MgO(l00) substrates indicate c‐axis orientation.

scholarly journals Low temperature preparation of α-tricalcium phosphate and its mechanical properties

2017 ◽  
Vol 11 (2) ◽  
pp. 100-105 ◽  
Author(s):  
Song Wang ◽  
Yaping Wang ◽  
Kangning Sun ◽  
Xiaoning Sun
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Tricalcium Phosphate ◽  
Annealing Temperature ◽  
Thermal Transformation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Temperature Preparation ◽  
Scanning Electron ◽  
Temperature Preparation

In this work, ?-tricalcium phosphate (?-TCP) was successfully prepared by the thermal transformation of amorphous calcium phosphate (ACP) precursor. ?-cyclodextrin (?-CD) was used for preparation of ACP precursor and played an important role in designing its special structure. The phase composition and microstructures of the obtained ?-TCP at different annealing temperature were analysed by X-ray diffraction and scanning electron microscope, and confirmed that ?-TCP can be prepared at 650?C for 3 h using ACP as precursor, which is much lower than the phase transition temperature of ?-TCP. Mechanical properties were tested 24 h after mixing the obtained ?-TCP with 30 wt.% of deionised water. The compressive strength and the flexural strength were 26.4MPa and 12.0MPa, respectively. The flexural strength was higher than that of ?-TCP prepared by other methods.

Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

1969 ◽  
Vol 27 ◽  
pp. 392-393
Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Outer Segment ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outer Segments ◽  
Retinal Rods ◽  
Temperature Electron ◽  
Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

Structure and Electronic Properties of Evaporated Thin Films of Lead Sulfide

2009 ◽  
Vol 294 ◽  
pp. 85-92 ◽  
Author(s):  
A.A. Ibrahim
Keyword(s):  
Thin Films ◽  
Lead Sulfide ◽  
Room Temperature ◽  
Conduction Band Edge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Temperature Electron ◽  
Transition Voltage ◽  
Dc Electrical Properties

Lead sulfide (PbS) thin films were prepared by thermal evaporation onto glass substrates from PbS powder. The structure and DC electrical properties of evaporated PbS thin film sandwich structures with thicknesses (d) up to 600 nm have been investigated. X-ray diffraction studies showed that the films were crystalline, with a preferred orientation in the [111] direction. Capacitance measurements indicated that the films had a relative permittivity of 5.7. Room-temperature current density-voltage (J–V) characteristics revealed ohmic conduction below a transition voltage (Vt) and a power–law dependence with an exponent of ≈ 2 at higher voltages. This behaviour was interpreted in terms of space–charge limited conductivity controlled by an exponential distribution of traps below the conduction band edge. Further evidence for this conduction process was provided by a linear dependence of Vt upon d2. Analysis of the results yielded a room temperature electron concentration no of ≈ (3.9 – 5.4) x 109 m-3.

Structure of in cell protein crystals containing organometallic complexes

2018 ◽  
Vol 20 (5) ◽  
pp. 2986-2989 ◽  
Author(s):  
Satoshi Abe ◽  
Kohei Atsumi ◽  
Keitaro Yamashita ◽  
Kunio Hirata ◽  
Hajime Mori ◽  
...  
Keyword(s):  
Organometallic Complexes ◽  
Molecular Structures ◽  
Protein Crystals ◽  
Cell Protein ◽  
X Ray Diffraction ◽  
X Ray

The molecular structures of in cell protein crystals containing organometallic Pd(allyl) complexes were determined by performing microfocus X-ray diffraction experiments.

Low Temperature Annealing of LPCVD Silicon Films

1987 ◽  
Vol 106 ◽  
Author(s):  
T. Aoyama ◽  
N. Konishi ◽  
T. Suzuki ◽  
K. Miyata
Keyword(s):  
Low Temperature ◽  
Spin Density ◽  
Electron Spin ◽  
High Electron ◽  
X Ray Diffraction ◽  
Electron Spin Density ◽  
X Ray ◽  
Low Temperature Annealing ◽  
Good Crystallinity ◽  
Temperature Electron

ABSTRACTLow temperature, 600°C annealing of LPCVD films was investigated by x-ray diffraction, ESR, TEM, and carrier mobility measurements. An optimum deposition temperature of about 550°C was found to yield good crystallinity and large electron mobility for annealed films; large grain sizes, a maximum crystallite size, and a maximum electron spin density were also observed for films deposited at the optimum temperature. Electron spin density for as-deposited films correlated with the crystalline volume by x-ray diffraction measurements on the films after annealing. This implys that only those amorphous components with high electron spin density can be converted into the crystalline phase by 600°C annealing.

Magnesiocanutite, NaMnMg2[AsO4]2[AsO2(OH)2], a new protonated alluaudite-group mineral from the Torrecillas mine, Iquique Province, Chile

2017 ◽  
Vol 81 (6) ◽  
pp. 1523-1531 ◽  
Author(s):  
Anthony R. Kampf ◽  
Barbara P. Nash ◽  
Dini Maurizio ◽  
Arturo A. Molina Donoso
Keyword(s):  
Structure Refinement ◽  
Secondary Phase ◽  
Obtuse Angle ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
Crystal Forms ◽  
X Ray ◽  
Temperature Electron ◽  
Mohs Hardness

AbstractThe new mineral magnesiocanutite (IMA2016-057), NaMnMg2[AsO4]2[AsO2(OH)2], was found at the Torrecillas mine, Iquique Province, Chile, where it occurs as a secondary phase in association with anhydrite, canutite, halite, lavendulan and magnesiokoritnigite. Magnesiocanutite occurs as pale brownish-pink to rose-pink, lozenge-shaped tablets that are often grouped in tightly intergrown aggregates. The crystal forms are {110} and {102}. Crystals are transparent, with vitreous lustre and white to very pale pink streak. The Mohs hardness is 2½, tenacity is brittle, and the fracture is splintery. Crystals exhibit two perfect cleavages: {010} and {101}. The calculated density is 3.957 g/cm3. Optically, magnesiocanutite is biaxial (+), with α = 1.689(2), β = 1.700(2), γ = 1.730(2) (measured in white light); 2Vmeas. = 64.3(4)°; slight dispersion, r <v; orientation Z = b; X ∧ a = 15° in obtuse angle β. The mineral is slowly soluble in dilute HCl at room temperature. Electron-microprobe analyses, provided Na2O 5.44, CaO 0.26, MgO 8.84, MnO 18.45, CoO 1.47, CuO 2.13, As2O5 59.51, H2O(calc) 2.86, total 98.96 wt.%. Magnesiocanutite is monoclinic, C2/c, a = 12.2514(8), b = 12.4980(9), c = 6.8345(5) Å, β = 113.167(8)°, V = 962.10(13) Å3 and Z = 4. The eight strongest powder X-ray diffraction lines are [dobs Å(I )(hkl)]: 6.25(42)(020), 3.566(43)(310,1̄31), 3.262(96)(1̄12), 3.120(59)(002,131,040,221), 2.787(93)(400,022,041,330), 2.718(100) (4̄21,240,112,402), 2.641(42)(1̄32) and 1.5026(43)(multiple). Magnesiocanutite has a protonated alluaudite-type structure (R1 = 2.59% for 789 Fo > 4σF reflections) and is the Mg analogue of canutite. Using the results of both the microprobe analyses and structure refinement, the structurally based empirical formula is Na(Mn0.78Mg0.22)Σ1.00(Mg1.04Mn0.70Cu0.15Co0.11)Σ2.00[AsO4]2[AsO2(OH)2].

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