Optical Anisotropy of RMnO3 Manganites in the Range of 4f-4f Transitions

2010 ◽  
Vol 168-169 ◽  
pp. 549-552 ◽  
Author(s):  
Natalia N. Loshkareva ◽  
Elena V. Mostovshchikova ◽  
A.S. Moskvin ◽  
Sergey V. Naumov ◽  
Natalia V. Kostromitina ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Anisotropy ◽  
Polarized Light ◽  
Transparency Window ◽  
Infrared Range ◽  
Spectral Features ◽  
Mid Infrared ◽  
Temperature Range ◽  
Hexagonal Manganites

Optical absorption of orthorhombic and hexagonal manganites RMnO3 (R= Pr3+, Gd3+, Sm3+, Eu3+, Ho3+, Tm3+, Er3+, and Yb3+) were studied in polarized light in the near- and mid-infrared range for the temperature range 80 - 300 K. Several spectral features associated with 4f-4f transitions of R3+ ions were found in the transparency window of RMnO3. Anisotropy of the absorption spectra in the range of multiplet 4f-4f transitions and changes in populations of the multiplet levels with temperature were observed.

scholarly journals Локализованные экситоны в спектре оптического поглощения оксида цинка, легированного марганцем

2019 ◽  
Vol 61 (5) ◽  
pp. 817
Author(s):  
В.И. Соколов ◽  
Н.Б. Груздев ◽  
В.А. Важенин ◽  
А.В. Фокин ◽  
А.В. Дружинин
Keyword(s):  
Zinc Oxide ◽  
Charge Transfer ◽  
Absorption Band ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Polarized Light ◽  
Threshold Energy ◽  
Impurity Absorption ◽  
Charge Transfer Transitions ◽  
Long Time

AbstractThe results of the study of optical absorption and EPR signals of single crystals of zinc oxide doped with manganese are presented. A broad impurity absorption band with the threshold energy about 2.1 eV, which was treated as a result of charge transfer transitions, has been observed for a long time in ZnO : Mn absorption spectra. In absorption spectra of a polarized light at 4.2 and 77.3 K, we first detected several lines of different intensity in a 1.877–1.936 eV range of energies of the light quanta. The observed lines are attributed to a donor exciton [( d ^5 + h ) e ] that emerges as a result of the Coulomb binding a free s electron and a hole, which is localized on p – d hybridized states. The EPR spectra of Mn^2+ ion signals, when corresponding to the impurity absorption band exposed to light, are found to be not photosensitive. The obtained results indicate that the ZnO : Mn impurity absorption is due to transitions from antibonding p – d hybridized DBH states to the conduction band.

scholarly journals Influence of Temperature on Water and Aqueous Glucose Absorption Spectra in the Near- and Mid-Infrared Regions at Physiologically Relevant Temperatures

2003 ◽  
Vol 57 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Peter Snoer Jensen ◽  
Jimmy Bak ◽  
Stefan Andersson-Engels
Keyword(s):  
Absorption Spectra ◽  
Near Infrared ◽  
Pure Water ◽  
Glucose Absorption ◽  
Diagnostic Methods ◽  
Effect Of Temperature ◽  
Difference Spectra ◽  
Absorption Bands ◽  
Mid Infrared ◽  
Temperature Range

Near- and mid-infrared absorption spectra of pure water and aqueous 1.0 g/dL glucose solutions in the wavenumber range 8000–950 cm−1 were measured in the temperature range 30–42 °C in steps of 2 °C. Measurements were carried out with an FT-IR spectrometer and a variable pathlength transmission cell controlled within 0.02 °C. Pathlengths of 50 μm and 0.4 mm were used in the mid- and near-infrared spectral region, respectively. Difference spectra were used to determine the effect of temperature on the water spectra quantitatively. These spectra were obtained by subtracting the 37 °C water spectrum from the spectra measured at other temperatures. The difference spectra reveal that the effect of temperature is highest in the vicinity of the strong absorption bands, with a number of isosbestic points with no temperature dependence and relatively flat plateaus in between. On the basis of these spectra, prospects for and limitations on data analysis for infrared diagnostic methods are discussed. As an example, the absorptive properties of glucose were studied in the same temperature range in order to determine the effect of temperature on the spectral shape of glucose. The change in water absorption associated with the addition of glucose has also been studied. An estimate of these effects is given and is related to the expected level of infrared signals from glucose in humans.

Infrared Studies of the Double Acceptor Zinc in Silicon

1989 ◽  
Vol 163 ◽  
Author(s):  
A. Dörnen ◽  
R. Kienle ◽  
K. Thonke ◽  
P. Stolz ◽  
G. Pensl ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Charge State ◽  
Crystal Field ◽  
Absorption Spectra ◽  
Ground State ◽  
Near Infrared ◽  
Mid Infrared ◽  
Absorption Studies ◽  
Infrared Studies ◽  
Neutral Charge State

AbstractIn the present paper, optical absorption studies on the neutral charge state of the double acceptor zinc in silicon are presented. Measurements were carried out in the mid infrared (MIR) and in the near infrared (NIR) region. The MIR absorption spectra show the excitation series of an effective-masslike hole, from which the Zn° level position is calculated to be at Ev + 319. 1 meV. A splitting of the ground state into 3 sublevels is assigned to hole-hole coupling and crystal-field splitting. Absorption spectra obtained in the NIR are interpreted in terms of an A° X-type bound exciton.

Optical absorption spectra of deoxy- and oxyhemoglobin in the temperature range 300—20 K

1986 ◽  
Vol 24 (3) ◽  
pp. 259-275 ◽  
Author(s):  
Lorenzo Cordone ◽  
Antonio Cupane ◽  
Maurizio Leone ◽  
Eugenio Vitrano
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Optical Absorption Spectra ◽  
Temperature Range

scholarly journals Low temperature mid-infrared cross-sections for peroxyacetyl nitrate (PAN) vapour

2005 ◽  
Vol 5 (4) ◽  
pp. 5669-5685
Author(s):  
G. Allen ◽  
J. J. Remedios ◽  
K. M. Smith
Keyword(s):  
Fourier Transform ◽  
Low Temperature ◽  
Absorption Spectra ◽  
Cross Sections ◽  
Spectral Resolution ◽  
Fourier Transform Infrared ◽  
Infrared Range ◽  
Peroxyacetyl Nitrate ◽  
Mid Infrared ◽  
Infrared Spectrometer

Abstract. Laboratory absorption spectra of peroxyacetyl nitrate (PAN, CH3C(O)OONO2) vapour have been measured in the mid-infrared range 550 cm−1 to 1400 cm−1 (18.2 to 7.14 µm) at both 250 K and 273 K, using a Fourier transform infrared spectrometer at a nominal spectral resolution of 0.25 cm−1 (unapodised). In addition, the 1600 cm

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