scholarly journals FAAS, FT-IR and XRD Identification of Natural and Heat Treated Opals Located in Wadla Woreda, North Wello, Ethiopia

2020 ◽  
pp. 1-8
Author(s):  
Adere Tarekegne Habte ◽  
Shiferaw Dessie Mekonnen ◽  
Adugna Nigatu Alene ◽  
Gietu Yirga Abate
Keyword(s):  
Optical Properties ◽  
Powder Diffraction ◽  
X Ray ◽  
Naturally Occurring ◽  
Heat Treated ◽  
Silica Materials ◽  
Hydrous Silica ◽  
Ft Ir ◽  
Diffraction Patterns ◽  
North Wollo

Opals are naturally occurring hydrous silica materials (SiO2*nH2O), and have been largely used in jewelry and as decorative elements in artworks due to their optical properties. In this study, we present some gemological properties, a combined spectroscopic (FAAS, FTIR) and X-ray powder diffraction (XRD) identification of natural and heat treated opals obtained from the main deposits in North Wollo, Ethiopia. The gemological measurements, FTIR and XRD spectra for natural and heat treated samples are nearly identical, FAAS shows clear differences on their color this may be due to the concentration differences of metals. Both of these opals showed spectra and diffraction patterns typical of Opal-CT, with clearly defined patterns and main peaks in the 2θ range of cristobalite and tridymite, called microcrystalline opals.

The occurrence of an orthorhombic high-temperature form of Ca2SiO4 (bredigite) in the Scawt Hill contact-zone and as a constituent of slags (With Plates XV and XVI.)

1948 ◽  
Vol 28 (200) ◽  
pp. 255-271 ◽  
Author(s):  
C. E. Tilley ◽  
H. C. G. Vincent
Keyword(s):  
Optical Properties ◽  
High Temperature ◽  
Low Temperature ◽  
Contact Zone ◽  
Powder Diffraction ◽  
Close Agreement ◽  
X Ray ◽  
Diffraction Patterns ◽  
Two Phases ◽  
High Temperature Form

Recent research on the polymorphism of calcium orthosilicate has broadened and to some extent modified the picture of the phase relations of this substance as presented in the pioneer studies of Day and Shepherd (1906) and Rankin and Wright (1915). These investigators recognized three distinct forms, α, β, and γ, related by transformation as follows: α⇄β at 1420° C. and β⇄γ, at 675° C. The high-temperature α form was described as monoclinic or triclinic and intimately twinned, the β form orthorhombic, and the low-temperature γ form as probably monoclinic. The optical properties of these α and β forms as reported are so closely similar that were it not for the twinning, regarded as diagnostic, the two forms would be distinguishable only with difficulty. This optical similarity was later found to be paralleled by a close agreement of the X-ray powder diffraction patterns of the two phases early noted by Hansen (1928) and confirmed among others by Insley (1936).

Two examples of quantitative analysis by simulated X-ray powder diffraction patterns

Clay Minerals ◽  
1982 ◽  
Vol 17 (4) ◽  
pp. 393-399
Author(s):  
C. E. Corbato ◽  
R. T. Tettenhorst
Keyword(s):  
Quantitative Analysis ◽  
Pattern Matching ◽  
Powder Diffraction ◽  
X Ray ◽  
Quantitative Estimates ◽  
Powder Diffractometer ◽  
Alternative Method ◽  
Two Samples ◽  
Natural Mixture ◽  
Diffraction Patterns

AbstractQuantitative estimates were made by visually matching computer-simulated with experimental X-ray powder diffractometer patterns for two samples. One was a natural mixture of dickite and nacrite in about equal proportions. The second sample contained mostly quartz with corundum and mullite in small (0.5–1%) amounts. Percentages deduced from pattern matching agreed to within ±10% of the weight fractions of the components determined by an alternative method of analysis.

Synchrotron X-ray studies of metal-organic framework M2(2,5-dihydroxyterephthalate), M = (Mn, Co, Ni, Zn) (MOF74)

2012 ◽  
Vol 27 (4) ◽  
pp. 256-262 ◽  
Author(s):  
W. Wong-Ng ◽  
J. A. Kaduk ◽  
H. Wu ◽  
M. Suchomel
Keyword(s):  
Powder Diffraction ◽  
Metal Organic Framework ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Lattice Parameter ◽  
X Ray ◽  
Metal Organic ◽  
Sorbent Materials ◽  
Diffraction Patterns ◽  
Unsaturated Metal Sites

M2(dhtp)·nH2O (M = Mn, Co, Ni, Zn; dhtp = 2,5-dihydroxyterephthalate), known as MOF74, is a family of excellent sorbent materials for CO2 that contains coordinatively unsaturated metal sites and a honeycomb-like structure featuring a broad one-dimensional channel. This paper describes the structural feature and provides reference X-ray powder diffraction patterns of these four isostructural compounds. The structures were determined using synchrotron diffraction data obtained at beam line 11-BM at the Advanced Photon Source (APS) in the Argonne National Laboratory. The samples were confirmed to be hexagonal R 3 (No. 148). From M = Mn, Co, Ni, to Zn, the lattice parameter a of MOF74 ranges from 26.131 73(4) Å to 26.5738(2) Å, c from 6.651 97(5) to 6.808 83(8) Å, and V ranges from 3948.08 Å3 to 4163.99 Å3, respectively. The four reference X-ray powder diffraction patterns have been submitted for inclusion in the Powder Diffraction File (PDF).

Synthesis, Characterization and Optical Properties of PLA / P3HT Blends Thin Films

2021 ◽  
Vol 19 (5) ◽  
pp. 132-138
Author(s):  
Maan Abd-Alameer Salih ◽  
Q.S. Kareem ◽  
Mohammed Hadi Shinen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spin Coating ◽  
Ring Opening ◽  
Energy Gap ◽  
Ring Opening Polymerization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conductivity Increase ◽  
Ft Ir

In this exploration Poly lactic corrosive (PLA) was orchestrated the ring-opening polymerization Poly lactic corrosive (PLA) blended with poly(3-hexylthiophene) (P3HT) which prepared by solution. Blends thin films Synthesis by spin coating technique and using Tetrahydrofuran (THF) as solvent. PLA powder was 'characterized by' 'X-ray' 'diffraction', '(FT-IR)'. pure Optical properties (PLA), (PLA)/P3HT blends thin films with different percentage of P3HT (0, 1, 2, and 3) wt% were investigated using UV-VS spectroscopy The results showed that the absorption, absorption coefficient, extinction coefficient and conductivity increase with increasing the rate of deformation P3HT, The energy gap decreases with increasing deformation.

scholarly journals Macroscopic x-ray powder diffraction imaging reveals Vermeer’s discriminating use of lead white pigments in Girl with a Pearl Earring

2019 ◽  
Vol 5 (8) ◽  
pp. eaax1975 ◽  
Author(s):  
S. De Meyer ◽  
F. Vanmeert ◽  
R. Vertongen ◽  
A. Van Loon ◽  
V. Gonzalez ◽  
...  
Keyword(s):  
Optical Properties ◽  
Powder Diffraction ◽  
Lead White ◽  
White Pigment ◽  
Microscopic Scale ◽  
X Ray ◽  
Oil Paintings ◽  
Johannes Vermeer ◽  
Diffraction Imaging ◽  
The 19Th Century

Until the 19th century, lead white was the most important white pigment used in oil paintings. Lead white is typically composed of two crystalline lead carbonates: hydrocerussite [2PbCO3·Pb(OH)2] and cerussite (PbCO3). Depending on the ratio between hydrocerussite and cerussite, lead white can be classified into different subtypes, each with different optical properties. Current methods to investigate and differentiate between lead white subtypes involve invasive sampling on a microscopic scale, introducing problems of paint damage and representativeness. In this study, a 17th century painting Girl with a Pearl Earring (by Johannes Vermeer, c. 1665, collection of the Mauritshuis, NL) was analyzed with a recently developed mobile and noninvasive macroscopic x-ray powder diffraction (MA-XRPD) scanner within the project Girl in the Spotlight. Four different subtypes of lead white were identified using XRPD imaging at the macroscopic and microscopic scale, implying that Vermeer was highly discriminatory in his use of lead white.

The Effect of Ethanol Solvent on Characterization of MAPbI3 Perovskite

2021 ◽  
Vol 1039 ◽  
pp. 307-312
Author(s):  
Mohammad Malik Abood ◽  
Osama Abdul Azeez Dakhil ◽  
Aref Saleh Baron
Keyword(s):  
Grain Size ◽  
Optical Properties ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Lead Iodide ◽  
X Ray ◽  
Diffraction Patterns ◽  
Photovoltaic Technologies ◽  
Perovskite Photovoltaic

Methyl ammonium lead iodide CH3NH3PbI3 Perovskite was synthesized by a new method mixing between one and two steps, in addition, the ethanol solvent was used to dissolve CH3NH3I and compared with isopropanol solvent. The characterizations of synthesized perovskite samples included the structural properties, morphological characteristics and optical properties. The intensity and orientation in X-ray diffraction patterns appear clearly in ethanol solvent while disappearing at a peak at 12o due to the speed reaction of perovskite in this solvent. Additionally, the ethanol solvent increasing the grain size of perovskite which homogeneity of the surface morphology. the ethanol solvent cause a decrease in the wavelength of absorbance edge in addition to an increase in the energy bandgap value. Keywords: Ethanol Solvent, Perovskite, Photovoltaic Technologies, X-ray diffraction.

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