Local ordering of chromium(III) in trioctahedral hydroxide sheets of stichtite studied by ion exchange chromatography

Clay Minerals ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 53-61 ◽  
Author(s):  
H. C. B. Hansen ◽  
C. Bender Koch
Keyword(s):  
Ion Chromatography ◽  
Exchange Chromatography ◽  
Cation Ordering ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Acid Dissolution ◽  
Absorption Bands ◽  
X Ray ◽  
Local Ordering

AbstractStichtite is the layered Mg-Cr(III) hydroxide carbonate of the pyroaurite group. The possibility of describing Cr(III) short range order (SRO) in stichtite by use of ion chromatography of the Cr(III)-hydroxo species following acid dissolution of the compound is described. Two synthetic stichtites of similar composition (average Mg5.73Cr(III)2.27(OH)15.93(O)0.07(CO3)1.10·xH2O) prepared in the absence or presence of hydroxy-bridged Cr(III) dimers and a sample from Dundas, Tasmania, Mg6.29Ni(II)0.02Cr(III)0.90Al0.65Fe(III)0.15(OH)15.26(OH2)0.74(CO3)1.23·xH2O have been examined. Ion chromatography showed the highest degree of SRO for the Dundas stichtite. For the synthetic stichtites the sample synthesized from Cr(III) dimers had the highest SRO. No information on cation ordering could be extracted from powder X-ray diffraction data. Visible spectroscopy indicates that for constant Mg:Cr(III) ratio the crystal field splitting increases with increasing SRO. Two different OH-stretching IR absorption bands (3585 and 3472 cm−1) are assigned to OH coordinated to 3Mg and OH coordinated to 2MgCr or Mg2Cr, respectively.

Effect of Temperature of Synthesis on X-Ray, Infrared Spectroscopic Study and Magnetic Properties of Magnesium Zinc Ferrites

2013 ◽  
Vol 547 ◽  
pp. 57-69 ◽  
Author(s):  
Sujata. S. Khot ◽  
Neelam S. Shinde ◽  
Bhimrao P. Ladgaonkar ◽  
Bharat B. Kale ◽  
Shrikant C. Watawe
Keyword(s):  
Curie Temperature ◽  
Saturation Magnetization ◽  
Ac Susceptibility ◽  
Lattice Parameter ◽  
Precipitation Method ◽  
Ir Absorption ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray

Some physical properties (such as lattice parameter, curie temperature, ac susceptibility) of Mg1-xZnxFe2O4 (where x = 0.3,0.4,0.5,0.6) ferrites have been studied. Magnesium Zinc Ferrites was synthesized by oxalate co-precipitation method at different synthesis temperature and characterized by X-ray diffraction and far IR absorption techniques, scanning Electron microscopy .The lattice parameter were computed. The X-ray diffraction studies reveal the formations of single phase cubic spinel structure.IR absorption bands are observed around 600 cm-1 and 400 cm-1 on the tetrahedral and octahedral sites respectively. Magnetization parameters such as saturation magnetization, and magnetic moment were calculated and the results are discussed with the help of the existing theories. Saturation magnetization was found to be in the range 2 emu/gm to 8.28 emu/gm when the samples were synthesized below 100°C. The variation of A.C. susceptibility with temperature shows the existence of super paramagnetic nature. The Curie temperature was determined from the measurement of the susceptibility verses temperature. The SEM micrograph shows the uniform distribution of the particles, the average size was estimated to be 0. 350 µm.

scholarly journals Synthesis, Structural and Electrical Studies of Li-Ni-Cu Nano Ferrites

2018 ◽  
Vol 26 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Shashidhar N. Adarakatti ◽  
Veeresh S. Pattar ◽  
Prashant K. Korishettar ◽  
Bhagyashri V. Grampurohit ◽  
Ravindra G. Kharabe ◽  
...  
Keyword(s):  
Spinel Ferrite ◽  
Unit Cell ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Absorption Bands ◽  
X Ray ◽  
Cell Parameters ◽  
Ir Absorption Spectra ◽  
Vegard’S Law

Abstract Li-Ni ferrite has gained great scientific elicit owing to of its unparalleled properties and applications. The copper doped Li-Ni ferrite has been synthesized by sucrose method. The structure was characterized by X-ray diffraction, which has confirmed the formation of single-phase spinel structure. X-ray diffraction and FTIR data reveals the formation of cubic structure phase. Unit cell parameters vary with copper content; overall variation of the unit cell parameters obeys Vegard’s law. The main absorption bands of spinel ferrite have appeared through IR absorption spectra recorded in the range of 300–700 cm−1. The copper concentration dependence of lattice parameters obeys Vegard’s law. DC electrical resistivity of the prepared samples decreases with increasing in the temperature which shows the semiconducting behaviour of all nano ferrites. The most prominent influence copper doping on the electrical properties of Li-Ni ferrites has been reported.

Synthesis of Galactomannan Sulfate-Citrate

2022 ◽  
Vol 1049 ◽  
pp. 218-223
Author(s):  
Aleksandr S. Kazachenko ◽  
Yuriy N. Malyar ◽  
Anna S. Kazachenko
Keyword(s):  
Biological Activity ◽  
Ftir Spectroscopy ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Mixed Ester ◽  
First Time ◽  
Derivatives Of

Sulfated derivatives of polysaccharides have anticoagulant, hypolipedimic and other biological activity. In this work, a complex mixed ester of galactomannan, its sulfate-citrate, was obtained for the first time. The introduction of citrate and sulfate groups was proved by FTIR spectroscopy by the appearance of corresponding absorption bands. It was shown by X-ray diffraction that the introduction of the citrate group leads to the amorphization of the galactomannan structure.

High pressure studies of Ni3[(C2H5N5)6(H2O)6](NO3)6·1.5H2O by Raman scattering, IR absorption, and synchrotron X-ray diffraction

RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 65031-65037 ◽  
Author(s):  
Junru Jiang ◽  
Jianguo Zhang ◽  
Peifen Zhu ◽  
Jianfu Li ◽  
Xiaoli Wang ◽  
...  
Keyword(s):  
Molecular Structure ◽  
High Pressure ◽  
Raman Scattering ◽  
Ir Absorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure Studies

Molecular structure (a) and packing diagram (b) of 1. The green, grey, blue, red, and white spheres denote Ni, C, N, O, and H atoms, respectively.

Darstellung von Mononitropentahydrohexaborat(2-) und Kristallstruktur von M2[B6H5(NO2)], M = K, Cs / Preparation of Mononitropentahydrohexaborate(2—) and Crystal Structure of M2[B6H5(NO2)], M = K, Cs

1993 ◽  
Vol 48 (12) ◽  
pp. 1727-1731 ◽  
Author(s):  
A. Franken ◽  
W. Preetz ◽  
M. Rath ◽  
K.-F. Hesse
Keyword(s):  
Crystal Structure ◽  
Ion Exchange ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dichloromethane Solution ◽  
Space Group ◽  
X Ray ◽  
Diethylaminoethyl Cellulose

By electrochemical oxidation of [B6H6]2- in the presence of nitrite ions and the base DBU in dichloromethane solution mononitropentahydrohexaborate [B6H5(NO2)]2- ions are formed and can be isolated by ion exchange chromatography on diethylaminoethyl cellulose. The crystal structures of the K and Cs salt were determined from single crystal X-ray diffraction analyses. K2[B6H5(NO2)] is monoclinic, space group P21/m with a = 5.953(1), b = 8.059(4), c = 8.906(1) Å, β = 109.553(9)°; Cs2[B6H5(NO2)] is monoclinic, space group P21/a with a = 9.438(6), b = 9.644(7), c = 11.138(9) Å, β = 101.44(9)°. The B6 octahedron is compressed in the direction of the B—NO2 bond by about 5%, with bond lengths between 1.67 and 1.77 A.

Structure ofT/emph>-phase superconductors: Anomalous x-ray-diffraction study of cation ordering inLA0.9Gd0.9Sr0.2CuO4

1990 ◽  
Vol 41 (4) ◽  
pp. 1889-1893 ◽  
Author(s):  
G. H. Kwei ◽  
R. B. Von Dreele ◽  
S-W. Cheong ◽  
Z. Fisk ◽  
J. D. Thompson
Keyword(s):  
Diffraction Study ◽  
Cation Ordering ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Bio Synthesis and Characterization of Silver Nanoparticles Using Lagenaria siceraria Leaf Extract and their Antibacterial Activity

2014 ◽  
Vol 38 ◽  
pp. 35-45 ◽  
Author(s):  
B. Anandh ◽  
A. Muthuvel ◽  
M. Emayavaramban
Keyword(s):  
Silver Nanoparticles ◽  
Leaf Extract ◽  
Face Centered Cubic ◽  
Lagenaria Siceraria ◽  
Human Pathogens ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Ft Ir ◽  
Uv Visible

The present investigation demonstrates the formation of silver nanoparticles by the reduction of the aqueous silver metal ions during exposure to the Lagenaria siceraria leaf extract. The synthesized AgNPs have characterized by UV-visible spectroscopy, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) techniques. AgNPs formation has screened by UV-visible spectroscopy through colour conversion due to surface plasma resonance band at 427 nm. X-ray diffraction (XRD) confirmed that the resulting AgNPs are highly crystalline and the structure is face centered cubic (fcc). FT-IR spectrum indicates the presence of different functional groups present in the biomolecules capping the nanoparticles. Further, inhibitory activity of AgNPs and leaf extract were tested against human pathogens like gram-pastive (Staphylococcus aureus, Bacillus subtilis), gram-negative (Escherichia coli and Pseudomonas aeruginosa). The results indicated that the AgNPs showed moderate inhibitory actions against human pathogens than Lagenaria siceraria leaf extract, demonstrating its antimicrobial value against pathogenic diseases

Chemical Synthesis and Properties of Layered Co1-yNiyO2-δOxides (0≤y≤1)

2000 ◽  
Vol 658 ◽  
Author(s):  
A. Manthiram ◽  
R. V. Chebiam ◽  
F. Prado
Keyword(s):  
Layer Structure ◽  
Magnetic Data ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Ni Content ◽  
Wet Chemical ◽  
Oxide Ions ◽  
Structure Layer

ABSTRACTLayered Co1-yNiyO2-δ oxides with 0≤y≤1 have been synthesized by chemically extracting lithium from LiNi1-yCoyO2 with NO2PF6 at ambient temperature. The samples have been characterized by X-ray diffraction, wet-chemical analyses, infrared spectroscopy, and magnetic susceptibility measurements. While NiO2-δ retains the initial O3 (CdCl2 structure) layer structure of LiNiO2, CoO2-δ consists of a mixture of P3 and O1 (CdI2 structure) phases that are formed by a sliding of the oxide ions in the initial O3 structure. CoO2-δ and NiO2-δ have oxygen contents of, respectively, 1.67 and 1.95 and the oxygen content increases with increasing Ni content, y, in Co1-yNiyO2-δ. While CoO2-δ exhibits metallic conductivity as revealed by theabsence of absorption bands in the infrared spectrum, NiO2-δ exhibits semiconducting behavior due to a completely filled t2g band. Magnetic data reveal a transition from antiferromagnetic to ferromagnetic correlations as the Ni content in Co1-yNiyO2-δ increases.

Investigations on Cu2+-substituted Ni–Zn ferrite nanoparticles

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650347
Author(s):  
Amarjeet ◽  
Vinod Kumar
Keyword(s):  
Spinel Phase ◽  
Thermo Gravimetric Analysis ◽  
Peak Position ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Zn Ferrite

[Formula: see text] ([Formula: see text] = 0.1, 0.3 and 0.5) nanoparticles were prepared by chemical co-precipitation method. The developed nanoparticles were characterized for structural properties by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Peak position in the X-ray diffraction pattern confirmed the single spinel phase of the developed particles. Infrared (IR) spectroscopy in mid-IR range showed the presence of characteristic absorption bands corresponding to octahedral and tetrahedral bonds in the spinel structure of prepared samples. Thermo-gravimetric analysis (TGA) measurements showed a considerable weight loss in the developed samples above 700[Formula: see text]C. Frequency dependence of the electrical properties of the developed material pellets was studied in the frequency range of 1 kHz–5 MHz. Temperature dependence of the dielectric constant of [Formula: see text] was studied at different temperatures, i.e. at 425, 450 and 475 K, in the frequency range of 1 kHz–5 MHz. It was found that the electrical conductivity decreases with increasing Cu[Formula: see text] ion content while it increases with the increase in temperature.

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