Ligand-field splitting ofFe2+in distorted octahedral sites of the magnesium-rich orthopyroxenesFexMg1−xSiO3: Correlation of magnetic susceptibility, Mössbauer, and optical absorption spectra

2001 ◽  
Vol 64 (14) ◽  
Author(s):  
G. Y. V. Victor ◽  
Debjani Ghosh ◽  
Subrata Ghose
Keyword(s):  
Magnetic Susceptibility ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Ligand Field ◽  
Optical Absorption Spectra ◽  
Field Splitting ◽  
Octahedral Sites ◽  
Distorted Octahedral

The optical absorption spectra of certain transition metal ions in muscovite, lepidolite, and fuchsite

1968 ◽  
Vol 5 (1) ◽  
pp. 31-38 ◽  
Author(s):  
G. H. Faye
Keyword(s):  
Transition Metal ◽  
Optical Absorption ◽  
Metal Ions ◽  
Absorption Spectra ◽  
Transition Metal Ions ◽  
Ligand Field ◽  
Optical Absorption Spectra ◽  
Ligand Field Theory ◽  
Octahedral Sites ◽  
Sheet Silicate

The unpolarized optical absorption spectra of the sheet silicate minerals muscovite, lepidolite, and fuchsite have been examined. The spectra, interpreted on the basis of ligand field theory, indicate that all three minerals contain Fe3+ and possibly Ti3+ in octahedral sites. In addition, muscovite is shown to contain octahedrally coordinated Fe2+, lepidolite octahedral Fe2+ and Mn2+, and fuchsite octahedral Cr3+. No evidence was found for transition metals in tetrahedral sites.Some comments are made on the similarity of the spectra of certain of the transition metal ions in several classes of minerals. This leads to the speculation that the cations Fe3+, Mn2+, and Cr3+ may tend to 'mold' their immediate surroundings.

Electron Paramagnetic Resonance and Optical Absorption Spectra of VO2+ in CsCl Single Crystals

1985 ◽  
Vol 40 (5) ◽  
pp. 511-515 ◽  
Author(s):  
G. Elbers ◽  
G. Lehmann
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Room Temperature ◽  
Ligand Field ◽  
Optical Absorption Spectra ◽  
Paramagnetic Resonance ◽  
Rapid Rotation ◽  
Vanadyl Ion ◽  
Vibrational Progression ◽  
Electron Paramagnetic

In vanadium-doped CsCl crystals grown from aqueous solutions anisotropic EPR spectra due to VO2+ are observed and analyzed at room temperature. Evidence is presented that isotropic spectra of this ion observed in this and other compounds are due to inclusions of growth solution and not to rapid rotation of the vanadyl ion in the solid as normally assumed. At 77 K a well resolved vibrational progression of about 820 cm −1 is observed in the first ligand field band of this ion. The optical absorption spectra indicate the presence of a second valence state of vanadium, most likely V3+, in varying proportions depending on the crystal growth temperature.

Impact of Cr3+ substitution on the nephelauxetic ratio and Racah parameter of Cr-Mn-Zn nanoferrites

2021 ◽  
Author(s):  
M. Abdo ◽  
M.S. Sadeq
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Tunable Laser ◽  
Ligand Field ◽  
Optical Absorption Spectra ◽  
B Values ◽  
Racah Parameter ◽  
Low Field ◽  
Optical Applications ◽  
First Time

Abstract For the first time, we present the ligand field splitting (10Dq) nephelauxetic ratio (β), Racah parameter (B) and stability of Cr3+ within Mn–Zn nanoferrite which synthesized using the citrate route. These parameters were determined via optical absorption spectra. The obtained bands in the significance range of optical absorption spectra are wide as well as asymmetric; therefore the deconvolution process becomes a necessary task. The values of 10Dq and B have been estimated from the produced bands. The values of 10Dq are observed to increase from 16366.61 to 16447.37 cm-1 whereas, B values are observed to decrease from 829.81 to 760.80 cm-1 with additional Cr3+ substitution. The increasing 10Dq and decreasing B values, evidence for bonds between Cr3+ ions with their environments became a further covalent (less ionic). Moreover, the values of β are observed to decrease for further Cr3+ substitution. This decrease of β produces less stability between Cr3+ and its ligand. Furthermore, Dq/B values declare that Cr3+ centers are in the low-field sites by a slight tendency towards the high-field sites with further Cr/Fe substitution process. Therefore, it was suggested that Cr3+ substituted Mn–Zn nanoferrites are excellent candidates for diverse optical applications such as a tunable laser.

scholarly journals Fast optical absorption spectra calculations for periodic solid state systems

2020 ◽  
Vol 15 (1) ◽  
pp. 89-113
Author(s):  
Felix Henneke ◽  
Lin Lin ◽  
Christian Vorwerk ◽  
Claudia Draxl ◽  
Rupert Klein ◽  
...  
Keyword(s):  
Solid State ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Absorption Spectra

NIR and Upconversion Luminescence Properties of Nd3+ Doped in Gd2O3-CaO-SiO2-B2O3 Glass System

2014 ◽  
Vol 548-549 ◽  
pp. 124-128 ◽  
Author(s):  
S. Insiripong ◽  
S. Kaewjeang ◽  
U. Maghanemi ◽  
H.J. Kim ◽  
N. Chanthima ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Concentration Quenching ◽  
Luminescence Spectra ◽  
Optical Absorption Spectra ◽  
Glass Matrices ◽  
Nir Luminescence

In this work, properties of Nd3+ in Gd2O3-CaO-SiO2-B2O3 glass systems with composition 25Gd2O3-10CaO-10SiO2-(55-x)B2O3-xNd2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% were investigated. The optical absorption spectra show peaks at 4F3/2 (877 nm) , 4F5/2+2H9/2 (802 nm), 4F7/2+4S3/2 (743 nm), 4F9/2 (682 nm), 2H11/2 (627 nm), 2G7/2 +4G5/2 (582 nm), 4G7/2 +2K13/2 (527 nm), 4G11/2 (481 nm), 2P1/2 (427 nm) and 2L15/2 + 4D1/2 + 1I11/2+ 4D5/2+ 4D3/2 (355 nm) reflecting the Nd3+ ions in glass matrices. The densities were increased with increasing of Nd2O3 concentration. This indicates the increase of the molecular weight by the replacement of B2O3 with a heavier Nd2O3 oxide in the glass. The upconversion luminescence spectra show bands at 393 nm for all Nd2O3 concentration and the strongest intensity from 2.5 % mol of Nd2O3 was obtained. For NIR luminescence, the intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1.5 mol% and beyond 1.5 mol% the concentration quenching is observed.

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