scholarly journals Raman Spectroscopic Characteristics of Zeolite Group Minerals

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 167
Author(s):  
Ying-Lai Tsai ◽  
Eugene Huang ◽  
Yu-Ho Li ◽  
Hsiao-Tien Hung ◽  
Jhih-Hao Jiang ◽  
...  
Keyword(s):  
Spectral Range ◽  
Vibration Modes ◽  
Characteristic Vibration ◽  
Characteristic Peak ◽  
Raman Spectroscopic ◽  
Additional Peak ◽  
Spectroscopic Characteristics ◽  
Raman Modes ◽  
Bending Modes ◽  
Fibrous Zeolites

In this work, Raman spectroscopic experiments are conducted on zeolites, including a total of 33 varieties and seven groups with different secondary structural frameworks, for which characteristic vibration modes are studied. Most of the zeolites show prominent Raman peaks in the spectral range between 200–1200 cm−1. Different groups of zeolites can be recognized by differences in the wavenumbers of the T-O-T (T = Si and Al, O = oxygen) modes in the range 379–538 cm−1, the M-O (M = metal,) modes in the range 250–360 cm−1 and the T-O bending modes in the range 530–575 cm−1. All zeolites show characteristic Raman peaks in the range 379–529 cm−1, except for natrolite group (fibrous) zeolites, which are characterized by T-O-T modes in the 433–447 cm−1 range and T-O bending modes in the 528–538 cm−1 range. The analcime group (with singly connected four-ring chains) zeolites show T-O-T modes in the 379–392 cm−1 and 475–497 cm−1 ranges. The gismondine group (with doubly connected four-ring chains) zeolites have T-O-T modes in the 391–432 cm−1 and 463–497 cm−1 ranges. The chabazite group (with a six-cyclic ring) zeolites are characterized by M-O modes in the 320–340 cm−1 range and T-O-T modes in the 477–509 cm−1 range. The Raman modes of mordenite group zeolites (397–410 cm−1 and 470–529 cm−1) overlap with those of heulandite group zeolites (402–416 cm−1 and 480–500 cm−1). Moreover, the mordenite group has a characteristic peak in the 502–529 cm−1 range, and an additional peak in the 800–965 cm−1 range. Another recognizable peak for the heulandite group is in the 612–620 cm−1 range. The unknown zeolites (cowlesite) have unique characteristic peaks at 534 cm−1, which can aid in the verification of their identity.

Spectroscopic Studies of a Superionic Plastic Phase Crystal: Lithium Sulfate

1988 ◽  
Vol 135 ◽  
Author(s):  
Roger Frech
Keyword(s):  
Lithium Ion ◽  
Spectroscopic Studies ◽  
Lithium Sulfate ◽  
Sulfate Ion ◽  
Raman Spectroscopic ◽  
Ion Interactions ◽  
Energy Environment ◽  
Plastic Phase ◽  
Bending Modes ◽  
Increasing Temperature

AbstractTemperature dependent Raman spectroscopic studies of single crystal lithium sulfate are summarized. Coupling between sulfate ion bending modes and the lithium ion translatory modes becomes weaker with increasing temperature until the lithium modes can no longer be observed above 250° C. The temperature interval above 450° in the monoclinic phase is marked by the onset of significant sulfate ion reorientational motion, as evidenced by the bandshape studies of the sulfate ion v1, mode and the librational modes. Bandshape analysis of the v3mode in the plastic phase strongly suggests that the symmetry of the sulfate ion potential energy environment has planar anisotropy.The lithium ion-sulfate ion interactions are modeled for correlated sulfate ion configurations as a function of lithium ion position. The results support the role of the octahedral site in lithium ion transitions contributing to the ionic conductivity.

scholarly journals Temperature dependent Raman Spectroscopic Study of the Fe doped La-=SUB=-0.67-=/SUB=-Sr-=SUB=-0.33-=/SUB=-MnO-=SUB=-3-=/SUB=- Prepared Using Ball Milling Method

2019 ◽  
Vol 61 (4) ◽  
pp. 741
Author(s):  
Nidhi Astik ◽  
Prafulla K. Jha ◽  
Vasant Sathe
Keyword(s):  
Average Crystallite Size ◽  
Sem Images ◽  
Raman Spectroscopic ◽  
Calcination Temperatures ◽  
Peak Broadening ◽  
Raman Modes ◽  
Milling Method ◽  
Scherrer Formula ◽  
Xrd Patterns ◽  
Increasing Temperature

AbstractPolycrystalline samples of La_0.67Sr_0.33Mn_0.65Fe_0.35O_3 (LSMFO) were synthesized using the standard ball mill method with different calcination temperatures ranging from 800 to 1100°C for 7 h. The phase purity of these samples was confirmed using X-ray diffraction (XRD) patterns. All samples were found to have rhombohedral crystal structure with $$R\bar {3}c$$ space group. The lattice parameters, cell volume, bond angle and bond length have been obtained using the Rietveld refinement by FullProf software. The average crystallite size calculated using the Debye-Scherrer formula was found between 27 and 60 nm. Surface morphology of the prepared samples has been examined using a scanning electron microscope (SEM). SEM images show the formation of well-arranged grain sizes distributed from 240 to 400 nm, much larger than one estimated using the Scherrer formula. All tiny particles are highly agglomerated with the increasing temperature and porosity decreases with increasing temperature. An analysis of the frequency and peak broadening of Raman modes as a function of temperature clearly shows the significant temperature effect on the A _1 g and E _ g modes of LSMFO. The shifts and broadening of the A _1 g and E _ g modes are discussed in light of the oxygen sublattice distortion. Our study shows the reduction in distortion with increasing calcination temperature, which suggests a decrease in the JT effect.

scholarly journals Microhydrated dihydrogen phosphate clusters probed by gas phase vibrational spectroscopy and first principles calculations

2015 ◽  
Vol 17 (39) ◽  
pp. 25714-25724 ◽  
Author(s):  
Shou-Tian Sun ◽  
Ling Jiang ◽  
J.W. Liu ◽  
Nadja Heine ◽  
Tara I. Yacovitch ◽  
...  
Keyword(s):  
Gas Phase ◽  
Vibrational Spectroscopy ◽  
Spectral Range ◽  
First Principles ◽  
Dihydrogen Phosphate ◽  
First Principles Calculations ◽  
Infrared Multiple Photon Dissociation ◽  
Bending Modes

We report infrared multiple photon dissociation spectra of cryogenically-cooled H2PO4−(H2O)n anions (n = 2–12) in the spectral range of the stretching and bending modes of the solute anion (600–1800 cm−1).

scholarly journals Raman modes in transferred bilayer CVD graphene

Open Physics ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Ahti Niilisk ◽  
Tauno Kahro ◽  
Valter Kiisk ◽  
Mihkel Rähn ◽  
Harry Alles ◽  
...  
Keyword(s):  
Spectroscopic Study ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Cvd Graphene ◽  
Raman Spectroscopic ◽  
Raman Spectroscopic Study ◽  
Layer Graphene ◽  
Raman Modes ◽  
Twisted Bilayer Graphene ◽  
Cu Foil

AbstractA systematic experimental Raman spectroscopic study of twisted bilayer graphene (tBLG) domains localized inside wide-area single layer graphene (SLG) produced by low-pressure CVD on Cu foil and transferred onto SiO

High-pressure Raman spectroscopic studies of FeS2 pyrite

2004 ◽  
Vol 68 (3) ◽  
pp. 433-441 ◽  
Author(s):  
A. K. Kleppe ◽  
A. P. Jephcoat
Keyword(s):  
Structural Phase ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Raman Resonance ◽  
X Ray ◽  
Resonance Effects ◽  
Raman Spectroscopic ◽  
Main Effect ◽  
Raman Modes ◽  
Diamond Anvil

AbstractWe report micro-Raman spectroscopic studies of FeS2 pyrite in the diamond-anvil cell under hydrostatic and non-hydrostatic conditions to 55 GPa at room temperature. Four out of five Ramanactive modes are resolved with helium as a pressure-transmitting medium to highest pressures. The fifth mode, Tg(2) [377 cm-1], is weak and unresolved lying ∼2 cm-1 from the intense Ag mode [379 cm-1] at 1 bar. We observe an increase in the separation of the Eg [344 cm-1] and Tg(1) [350 cm-1] modes under compression. All observed frequencies increase continuously with increasing pressure showing no evidence for a structural phase transition in accord with both X-ray diffraction and shock-wave studies. The Ag and Tg(1) modes gain significantly in intensity relative to the Eg mode with increasing pressure probably resulting from Raman resonance effects. The Tg(3) mode [430 cm-1] broadens unusually compared to the other pyrite modes with pressure. The Raman data are consistent with a contraction of the S-S and Fe-S bonds under pressure. The main effect of non-hydrostatic conditions on the Raman modes is a strong pressure-induced broadening; the pressure-dependence of the frequencies and relative intensities are not affected within the error of the measurements.

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