Spectroscopic study of the surface of zeolite Y. II. Infrared spectra of structural hydroxyl groups and adsorbed water on alkali, alkaline earth, and rare earth ion-exchanged zeolites

1968 ◽  
Vol 72 (12) ◽  
pp. 4211-4223 ◽  
Author(s):  
John William Ward
Keyword(s):  
Rare Earth ◽  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Alkaline Earth ◽  
Zeolite Y ◽  
Adsorbed Water ◽  
Hydroxyl Groups ◽  
Rare Earth Ion ◽  
Structural Hydroxyl

Diffuse reflectance infrared spectra of kaolinite and kaolinite/alkali halide mixtures. Curve-fitting of the OH stretching region

1991 ◽  
Vol 69 (11) ◽  
pp. 1786-1790 ◽  
Author(s):  
K. H. Michaelian ◽  
W. I. Friesen ◽  
S. Yariv ◽  
A. Nasser
Keyword(s):  
Infrared Spectra ◽  
Curve Fitting ◽  
Alkali Halide ◽  
Diffuse Reflectance ◽  
Alkali Halides ◽  
Hydroxyl Groups ◽  
Caesium Chloride ◽  
Inner Surface ◽  
Structural Hydroxyl ◽  
Diffuse Reflectance Infrared

Diffuse reflectance infrared spectra of kaolinite and binary mixtures of this clay with alkali halides have been analysed using curve-fitting and deconvolution. For caesium chloride and caesium bromide, decomposition of the hydroxyl stretching region has made it possible to correlate the positions and intensities of bands due to structural hydroxyl groups of kaolinite, or to intercalated water, with the degree of intercalation. One of these bands, arising from uncoupled inner surface OH stretching in kaolinite, is not identifiable in spectra of the uncomplexed clay or mixtures where intercalation did not occur. A new band revealed by curve-fitting spectra of intercalated samples is attributed either to water at the interface between the clay and the alkali halide, or to an FeO—H impurity in the kaolinite. Key words: kaolinite, infrared, curve-fitting.

Proton MAS NMR studies of hydroxyl groups in alkaline earth cation-exchanged zeolite Y

1989 ◽  
Vol 163 (2-3) ◽  
pp. 221-224 ◽  
Author(s):  
Michael Hunger ◽  
Dieter Freude ◽  
Harry Pfeifer ◽  
Dagmar Prager ◽  
Wladimir Reschetilowski
Keyword(s):  
Alkaline Earth ◽  
Zeolite Y ◽  
Mas Nmr ◽  
Hydroxyl Groups ◽  
Nmr Studies ◽  
Alkaline Earth Cation ◽  
Earth Cation

Rare-earth ion exchange in zeolite Y

Zeolites ◽  
1986 ◽  
Vol 6 (3) ◽  
pp. 201-205 ◽  
Author(s):  
Lovat V.C. Rees ◽  
Tao Zuyi
Keyword(s):  
Rare Earth ◽  
Ion Exchange ◽  
Zeolite Y ◽  
Rare Earth Ion

Infrared spectroscopy of ferrihydrite: evidence for the presence of structural hydroxyl groups

Clay Minerals ◽  
1979 ◽  
Vol 14 (2) ◽  
pp. 109-114 ◽  
Author(s):  
J. D. Russell
Keyword(s):  
Infrared Spectroscopy ◽  
Ir Spectroscopy ◽  
Room Temperature ◽  
Adsorbed Water ◽  
Deformation Vibration ◽  
Hydroxyl Groups ◽  
Absorption Bands ◽  
Oh Groups ◽  
Structural Hydroxyl

AbstractIR spectroscopy has shown that adsorbed water is almost completely removed from ferrihydrite by evacuation at room temperature. Absorption bands at 3615 and 3430 cm−1 appearing thereafter are interpreted as arising from OH groups located respectively at the surface and deeper in the structure. These groups are readily converted to OD on treatment with D2O vapour and this has allowed the OH deformation vibration to be identified at 800 cm−1. It is proposed that OH groups in ferrihydrite are about half as numerous as those in akaganéite (β-FeOOH) and that they may occur in environments similar to those in this mineral. The formula for ferrihydrite proposed by earlier workers, 5 Fe2O3.9H2O, should thus be amended to Fe2O3. 2 FeOOH.2·6H2O in order to indicate the presence of structural OH groups. A re-appraisal of the ferrihydrite structure appears desirable.

Phase composition of modern microcrystalline modifiers containing silicon, alkaline earth and rare earth metals

2020 ◽  
pp. 25-34
Author(s):  
V. P. Ermakova ◽  
◽  
S. Yu. Melchakov ◽  
V. G. Smirnova ◽  
L. A. Ovchinnikova ◽  
...  
Keyword(s):  
Rare Earth ◽  
Phase Composition ◽  
Alkaline Earth ◽  
Rare Earth Metals

Infrared spectroscopic study of the YPO4-YCrO4 system

1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek
Keyword(s):  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Point Of View ◽  
Mixed Crystals ◽  
Crystal Symmetry ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectroscopic ◽  
Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

scholarly journals Structure, Luminescence, and Magnetic Properties of Crystalline Manganese Tungstate Doped with Rare Earth Ion

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Jae-Young Jung ◽  
Soung-Soo Yi ◽  
Dong-Hyun Hwang ◽  
Chang-Sik Son
Keyword(s):  
Magnetic Field ◽  
Rare Earth ◽  
Sintering Temperature ◽  
Luminescent Properties ◽  
Concentration Quenching ◽  
Rare Earth Ions ◽  
Precipitation Method ◽  
Rare Earth Ion ◽  
Co Precipitation ◽  
Quenching Phenomenon

The precursor prepared by co-precipitation method was sintered at various temperatures to synthesize crystalline manganese tungstate (MnWO4). Sintered MnWO4 showed the best crystallinity at a sintering temperature of 800 °C. Rare earth ion (Dysprosium; Dy3+) was added when preparing the precursor to enhance the magnetic and luminescent properties of crystalline MnWO4 based on these sintering temperature conditions. As the amount of rare earth ions was changed, the magnetic and luminescent characteristics were enhanced; however, after 0.1 mol.%, the luminescent characteristics decreased due to the concentration quenching phenomenon. In addition, a composite was prepared by mixing MnWO4 powder, with enhanced magnetism and luminescence properties due to the addition of dysprosium, with epoxy. To one of the two prepared composites a magnetic field was applied to induce alignment of the MnWO4 particles. Aligned particles showed stronger luminescence than the composite sample prepared with unsorted particles. As a result of this, it was suggested that it can be used as phosphor and a photosensitizer by utilizing the magnetic and luminescent properties of the synthesized MnWO4 powder with the addition of rare earth ions.

ChemInform Abstract: RADIOCRYSTALLOGRAPHIC AND OPTICAL STUDY OF DOUBLE RARE EARTH AND ALKALINE EARTH GALLATES

1978 ◽  
Vol 9 (5) ◽  
Author(s):  
NGUYEN-TRUT-DINH NGUYEN-TRUT-DINH ◽  
G. LE FLEM ◽  
J. FAVA ◽  
A. DAOUDI ◽  
G. DEMAZEAU
Keyword(s):  
Rare Earth ◽  
Alkaline Earth ◽  
Optical Study
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