The thermal behaviour of an Fe-rich illite

Clay Minerals ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 45-52 ◽  
Author(s):  
E. Murad ◽  
U. Wagner
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Room Temperature ◽  
Phase Changes ◽  
X Ray ◽  
Structural Breakdown ◽  
Characteristic Features ◽  
Diffraction Patterns ◽  
Good Agreement ◽  
Subsequent Disappearance

AbstractThe phase changes that took place upon heating an Fe-rich illite (OECD #5) to 1300°C in an oxidizing atmosphere were studied by a variety of mineralogical techniques. Infrared spectra, showing the stepwise dehydroxylation of the illite, showed good agreement with variations in sample colour and Mössbauer spectra. Dehydroxylation did not lead to noticeable variations in X-ray powder diffraction patterns until the structural breakdown of illite and formation of new phases at about 900°C Mössbauer spectroscopy proved to be very sensitive to all changes induced by heating, showing the disappearance of Fe2+ at 250°C, the gradual dehydroxylation between about 350 and 900°C, and characteristic features of the products formed at higher temperatures, e.g. the formation of hematite as the illite structure breaks down and the subsequent disappearance of hematite due to the incorporation of Fe in glass above 1200°C. The formation of hematite in clusters large enough to order magnetically at room temperature was first observed in the sample heated to 900°C, whereas at 4.2 K, significant proportions of a magnetically ordered phase could already be identified in the sample heated to 650°C.

Evaluation of Reference X-ray Diffraction Patterns in the ICDD Powder Diffraction File

1990 ◽  
Vol 34 ◽  
pp. 369-376
Author(s):  
G. J. McCarthy ◽  
J. M. Holzer ◽  
W. M. Syvinski ◽  
K. J. Martin ◽  
R. G. Garvey
Keyword(s):  
Powder Diffraction ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
Cd Rom ◽  
X Ray ◽  
Binary Oxides ◽  
Diffraction Patterns ◽  
Input Format ◽  
Good Agreement

AbstractProcedures and tools for evaluation of reference x-ray powder patterns in the JCPDSICDD Powder Diffraction File are illustrated by a review of air-stable binary oxides. The reference patterns are evaluated using an available microcomputer version of the NBS*A1DS83 editorial program and PDF patterns retrieved directly from the CD-ROM in the program's input format. The patterns are compared to calculated and experimental diffractograms. The majority of the oxide patterns have been found to be in good agreement with the calculated and observed diffractograms, but are often missing some weak reflections routinely observed with a modern diffractometer. These weak reflections are added to the PDF pattern. For the remainder of the phases, patterns are redetermined.

X-ray powder diffraction data for compound DyNiSn

1997 ◽  
Vol 12 (3) ◽  
pp. 134-135
Author(s):  
Liangqin Nong ◽  
Lingmin Zeng ◽  
Jianmin Hao
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Diffraction Patterns

The compound DyNiSn has been studied by X-ray powder diffraction. The X-ray diffraction patterns for this compound at room temperature are reported. DyNiSn is orthorhombic with lattice parameters a=7.1018(1) Å, b=7.6599(2) Å, c=4.4461(2) Å, space group Pna21 and 4 formula units of DyNiSn in unit cell. The Smith and Snyder Figure-of-Merit F30 for this powder pattern is 26.7(0.0178,63).

X-ray powder diffraction data of anilinium trimolybdate tetrahydrate and anilinium trimolybdate dihydrate

1999 ◽  
Vol 14 (4) ◽  
pp. 280-283 ◽  
Author(s):  
A. Rafalska-Łasocha ◽  
W. Łasocha ◽  
M. Michalec
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Room Temperature ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Diffraction Patterns

The X-ray powder diffraction patterns of anilinium trimolybdate tetrahydrate, (C6H5NH3)2Mo3O10·4H2O, and anilinium trimolybdate dihyhydrate, (C6H5NH3)2Mo3O10·2H2O, have been measured in room temperature. The unit cell parameters were refined to a=11.0670(7) Å, b=7.6116(8) Å, c=25.554(3) Å, space group Pnma(62) and a=17.560(2) Å, b=7.5621(6) Å, c=16.284(2) Å, β=108.54(1)°, space group P21(4) or P21/m(11) for orthorhombic anilinium trimolybdate tetrahydrate and monoclinic anilinium trimolybdate dihydrate, respectively.

Identification of two lead perovskites, Pb2ScTaO6 and Pb(Sc0.5Nb0.5)O3, by X-ray powder diffraction patterns

1993 ◽  
Vol 8 (3) ◽  
pp. 191-193 ◽  
Author(s):  
C. Caranoni ◽  
P. Lampin ◽  
C. Boulesteix
Keyword(s):  
Single Crystals ◽  
Powder Diffraction ◽  
Perovskite Structure ◽  
Room Temperature ◽  
Stoichiometric Mixture ◽  
High Quality ◽  
Space Group ◽  
X Ray ◽  
Diffraction Patterns ◽  
Degree Of Order

Substituting cations in materials with the formula Pb2B′B″O6 is more or less ordered on the B sites. High-quality single crystals of Pb2ScTaO6 (PST) and Pb(Sc0.5Nb0.5)O3 (PSN) were prepared from two thermal cycles. A stoichiometric mixture of the constituent oxides was prefired at up to 1000 °C, and then crystals were grown from a PbO–B2O3–PbF2 flux mixture, starting at a temperature of 1100 °C for PSN and 1200 °C for PST. At room temperature, X-ray examination showed that PSN had a perovskite structure with a cubic unit-cell and a refined parameter a = 4.080(1 ) Å, space group Pm3m and Z = 1, whereas PST formed a well-ordered superlattice with a = 8.136(1) Å, Z = 4 and space group Fm3m. In each case a fully indexed powder pattern is presented. The degree of order is estimated to be close to 80% for PST and less than 10% for PSN.

Powder diffraction investigations of naphthalenesulfonic acids and their complexes with DMAN

2004 ◽  
Vol 19 (4) ◽  
pp. 378-384
Author(s):  
A. Rafalska-Lasocha ◽  
M. Grzywa ◽  
B. Włodarczyk-Gajda ◽  
W. Lasocha
Keyword(s):  
Powder Diffraction ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Acid Hydrate ◽  
M 12 ◽  
Diffraction Patterns

The X-ray diffraction patterns of two organic acids 1-naphthalenesulfonic acid dihydrate and 2-naphthalenesulfonic acid hydrate were measured at room temperature. Complexes of these acids with 1,8-bis(dimethylamino)naphthalene (DMAN) were synthesized, purified and investigated by means of X-ray powder diffraction. 1-Naphthalenesulfonic acid dihydrate as well as its complex with 1,8-bis(dimethylamino)naphthalene crystallize in the monoclinic system with unit cell parameters refined to a=0.91531(8) nm, b=0.7919(1) nm, c=0.8184(1) nm, β=101.618(9)° space group P21/m (11) and a=1.7781(4) nm, b=2.0122(4) nm, c=1.2337(2) nm, β=96.54(3)°, space group C2/m (12), respectively. 2-Naphthalenesulfonic acid hydrate crystallizes in the orthorhombic system with a=2.2749(3) nm, b=0.7745(1) nm, c=0.591 36(9) nm, space group Pnma, whereas its complex with 1,8-bis(dimethylamino)naphthalene crystallizes in the triclinic system a=1.3969(6) nm, b=1.4292(5) nm, c=1.1741(6) nm, α=90.93(3)°, β=98.14(3)°, γ=113.93(3)°, space group P-1 (2).

Physico-Chemical Characterization of Some 5,5-Disubstituted-1,3-Dixanthyl Barbituric Acids

1967 ◽  
Vol 21 (4) ◽  
pp. 225-231 ◽  
Author(s):  
B. C. Flann ◽  
J. A. R. Cloutier
Keyword(s):  
Experimental Data ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Chemical Characterization ◽  
Melting Points ◽  
X Ray ◽  
Physico Chemical ◽  
Diffraction Patterns ◽  
Derivatives Of

The dixanthyl derivatives of 21 clinically important barbituric acids have been prepared. Melting points, infrared spectra, and x-ray powder-diffraction patterns of the purified compounds are presented. Infrared evidence is used to discuss the position of the linkage between the xanthyl and barbiturate portions of the derivatives. The experimental data should prove of particular value for the microchemical identification of barbiturates.

X-ray powder diffraction studies of aniline derivatives

2003 ◽  
Vol 18 (3) ◽  
pp. 266-268
Author(s):  
A. Rafalska-Łasocha ◽  
W. Łasocha
Keyword(s):  
Powder Diffraction ◽  
Room Temperature ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Orthorhombic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Aniline Derivatives ◽  
Diffraction Patterns

The X-ray powder diffraction patterns of two liquid aniline derivatives o-chloroaniline, and m-chloroaniline were measured at 250 °K in a low temperature chamber. Both compounds crystallize in the orthorhombic system with the unit cell parameters refined to a=1.8391(3) nm, b=1.0357(2) nm, c=0.6092(1) nm, space group Pmmm(47) and a=0.450 39(9) nm, b=1.9820(4) nm, c=1.2699(4) nm, space group Pcca(54) for o-chloroaniline and m-chloroaniline, respectively. Investigated at room temperature, 2,6-dichloroaniline crystallizes in the monoclinic system, space group P21/c(14), a=1.1329(2) nm, b=0.41093(8) nm, c=1.5445(3) nm, α=γ=90° β=99.96(2)°.

X-ray powder diffraction data and thermal expansion of N(CH3)4Br and N(CH3)4I

1996 ◽  
Vol 11 (3) ◽  
pp. 246-249 ◽  
Author(s):  
Alex Xenopoulos ◽  
Martina Ralle ◽  
Anton Habenschuss ◽  
Bernhard Wunderlich
Keyword(s):  
Thermal Expansion ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Chem Phys ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Tetramethylammonium Bromide ◽  
Diffraction Patterns

The X-ray powder diffraction patterns for tetramethylammonium bromide and iodide have been measured from near room temperature up to decomposition/sublimation. The unit cell parameters were refined and the coefficients of thermal expansion calculated. Unlike N(CH3)4Cl [M. Stammler, J. Inorg. Nucl. Chem. 29, 2203–2221 (1967)], N(CH3)4Br (1Br) and N(CH3)4I (1I) undergo no solid–solid transitions before decomposition/sublimation as was observed earlier by thermal analysis [S. S. Chang and E. F. Westrum, J. Chem. Phys. 36(9), 2420–2423 (1962); Coulter etal., J. Am. Chem. Soc. 62, 2845–2851 (1940); Xenopoulos etal., Mol. Cryst. Liq. Cryst. 214, 63–79 (1992)].

Studies of the phosphorodiamidates of alkali metals

1969 ◽  
Vol 47 (14) ◽  
pp. 2613-2617 ◽  
Author(s):  
Y. N. Sadana
Keyword(s):  
Powder Diffraction ◽  
Infrared Spectra ◽  
Alkali Metals ◽  
Potassium Salts ◽  
X Ray ◽  
Diffraction Patterns ◽  
Sodium And Potassium

Phosphorodiamidates of lithium, rubidium, and cesium have been prepared and characterized. The infrared spectra and the X-ray powder diffraction patterns of these and the previously known sodium and potassium salts have been recorded and discussed.

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