scholarly journals Band structure and cluster model calculations of LaNiO3 compared to photoemission, O 1s X-ray absorption, and optical absorption spectra

2019 ◽  
Vol 383 (24) ◽  
pp. 2952-2956
Author(s):  
E. Alves ◽  
H.P. Martins ◽  
S. Domenech ◽  
M. Abbate
2001 ◽  
Vol 16 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Kohei Fukumi ◽  
Akiyoshi Chayahara ◽  
Kohei Kadono ◽  
Hiroyuki Kageyama ◽  
Tomoko Akai ◽  
...  

Coordination structures of implanted Fe, Co, and Ni ions were studied in 1.78–2.00-MeV 5 × 1016 ions/cm2-implanted silica glasses by x-ray absorption and optical absorption spectroscopies. It was found from x-ray absorption spectra that the implanted Fe, Co, and Ni ions are coordinated by ca.3 oxygen atoms. The implanted ions dispersed in glass matrix and did not form crystals. The valence of the implanted ions was about 1.5. The Fe–O, Co–O, and Ni–O interatomic distances were 190, 191, and 192 pm, respectively. In addition, it was found from optical absorption spectra that one-fifth of implanted Co ions were present as Co2+ ions in tetrahedral symmetry.


2004 ◽  
Vol 377 (1-2) ◽  
pp. 25-28 ◽  
Author(s):  
J. Manica ◽  
M. Abbate ◽  
J.E. Gayone ◽  
J.A. Guevara ◽  
S.L. Cuffini

2010 ◽  
Vol 7 (2) ◽  
pp. 425-432
Author(s):  
P. Eswaran ◽  
A. Anbagi ◽  
S. Nagarajan

Optical absorption spectra of KBr:Tl+(0.0125 mol%) single crystals shows A, B and C bands around 258, 220 and 210 nm respectively. In KCl0.1Br0.9:Tl+(0.0125 mol%) mixed crystals exhibit slightly broadening of the A-band towards lower wavelength side. The broadening of the absorption spectra are suggested to be due to some complex Tl+centers involving Br-and Cl-ions formed in the mixed crystals. When excited at A, B and C-bands of Tl+ions, PL of KBr:Tl+showed emission band around 320 with a prominent shoulder around 365 nm. In KCl0.1Br0.9mixed crystals the shoulder around 365 nm is not prominent due to the perturbing influence of Cl-ions. Addition bands in the excitation spectra are attributed to the presence of Tl+dimmers. PSL observed in X-ray irradiated crystals resembled their respective PL emissions indicating that PSL in them is due to Tl+ions.


2017 ◽  
Vol 31 (13) ◽  
pp. 1750101 ◽  
Author(s):  
Ibrahim Bulus ◽  
S. A. Dalhatu ◽  
R. Hussin ◽  
W. N. Wan Shamsuri ◽  
Y. A. Yamusa

Achieving outstanding physical and optical properties of borosulfophosphate glasses via controlled doping of rare earth ions is the key issue in the fabrication of new and highly-efficient glass material for diverse optical applications. Thus, the effect of replacing P2O5 by Dy2O3 on the physical and optical properties of Dy[Formula: see text]-doped lithium-borosulfophosphate glasses with chemical composition of 15Li2O–30B2O3–15SO3–[Formula: see text]P2O5–[Formula: see text]Dy2O3 (where 0.0 mol.% [Formula: see text] mol.%) has been investigated. The glass samples were synthesized from high-purity raw materials via convectional melt-quenching technique and characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectrometry (EDX), density and UV–vis–NIR absorption measurements. The amorphous nature of the prepared glass samples was confirmed by XRD patterns whereas the EDX spectrum depicts elemental traces of O, C, B, S, P and Dy. The physical parameters such as density, refractive index, molar volume, polaron radius and field strength were found to vary nonlinearly with increasing Dy2O3 concentration. UV–vis–NIR absorption spectra revealed seven absorption bands with most dominant peak at 1269 nm (6H[Formula: see text]F[Formula: see text]H[Formula: see text]). From the optical absorption spectra, the optical bandgap and Urbach’s energy have been determined and are related with the structural changes occurring in these glasses with increase in Dy2O3 content. Meanwhile, the bonding parameters ([Formula: see text]) evaluated from the optical absorption spectra were found to be ionic in nature. The superior features exhibited by the current glasses nominate them as potential candidate for nonlinear optical applications.


ChemInform ◽  
2004 ◽  
Vol 35 (44) ◽  
Author(s):  
J. Manica ◽  
M. Abbate ◽  
J. E. Gayone ◽  
J. A. Guevara ◽  
S. L. Cuffini

2001 ◽  
Vol 693 ◽  
Author(s):  
M. E. Little ◽  
M. E. Kordesch

AbstractReactive sputtering was used to grow thin films of ScxGa1-xN with scandium concentrations of 20%-70% on quartz substrates at temperatures of 300-675 K. X-ray diffraction (XRD) of the films showed either weak or no structure, suggesting the films are amorphous or microcrystalline. Optical absorption spectra were taken of each sample and the optical band gap was determined. The band gap varied linearly with increasing Ga concentration between 2.0 and 3.5 eV. Ellipsometry was used to confirm the band gap measurements and provide optical constants in the range 250-1200 nm. ScN and GaN have different crystal structures (rocksalt and wurzite, respectively), and thus may form a heterogeneous mixture as opposed to an alloy. Since the XRD data were inconclusive, bilayers of ScN/GaN were grown and optical absorption spectra taken. A fundamental difference in the spectra between the bilayer films and alloy films was seen, suggesting the films are alloys, not herterogeneous mixtures.


JETP Letters ◽  
2019 ◽  
Vol 110 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Ya. V. Zhumagulov ◽  
A. V. Krasavin ◽  
A. E. Lukyanov ◽  
V. D. Neverov ◽  
A. A. Yaroslavtsev ◽  
...  

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