Anomalous shape of the IR absorption lines in an expanding molecular beam of ammonia

1984 ◽  
Vol 41 (13) ◽  
pp. 439-442 ◽  
Author(s):  
G. Baldacchini ◽  
S. Marchetti ◽  
V. Montelatici
Keyword(s):  
Molecular Beam ◽  
Absorption Lines ◽  
Ir Absorption ◽  
Anomalous Shape

Interaction energy of water dimers from pressure broadening of near-IR absorption lines

2008 ◽  
Vol 462 (4-6) ◽  
pp. 188-191 ◽  
Author(s):  
Phyllis A.Y. Fiadzomor ◽  
Anthony M. Keen ◽  
Robert B. Grant ◽  
Andrew J. Orr-Ewing
Keyword(s):  
Interaction Energy ◽  
Absorption Lines ◽  
Ir Absorption ◽  
Pressure Broadening ◽  
Near Ir ◽  
Water Dimers

SPECTROSCOPIC PROPERTIES OF B2O3–PbO–Nd2O3 GLASSES

1999 ◽  
Vol 13 (24) ◽  
pp. 879-884 ◽  
Author(s):  
V. SIMON ◽  
I. ARDELEAN ◽  
I. MILEA ◽  
M. PETEANU ◽  
S. SIMON
Keyword(s):  
Glass Matrix ◽  
Spectroscopic Properties ◽  
Glass System ◽  
Absorption Lines ◽  
Local Order ◽  
Ir Absorption ◽  
Lead Borate ◽  
Absorption Bands ◽  
Lanthanide Ion ◽  
Radiative Transitions

Samples belonging to x Nd 2 O 3(100-x) [ 2B 2 O 3· PbO ] glass system, with 0≤ x≤ 40 mol%, are investigated by IR and UV–VIS spectroscopies in order to obtain evidence for the influence of Nd 2 O 3 on the local order from 2B 2 O 3· PbO glass matrix. Besides the IR absorption bands characteristic to lead and boron arrangements, typical absorption lines of Nd 3+ ions around 4000 cm -1 and 6000 cm -1 are recorded. The 6000 cm -1 band appears only for the samples with x≥25 mol% Nd 2 O 3. The split of some UV–VIS absorption bands arising from transitions of neodymium ions in doublet lines as well as the shift of the absorption bands as the Nd 2 O 3 content increases denote the influence of the lead–borate matrix on the radiative transitions of the lanthanide ion.

Infrared Absorption from Low Carbon Concentration, Low Dose, Annealed CZ Silicon

2007 ◽  
Vol 131-133 ◽  
pp. 207-212 ◽  
Author(s):  
N. Inoue ◽  
Y. Goto ◽  
T. Sugiyama
Keyword(s):  
Infrared Absorption ◽  
Carbon Concentration ◽  
Low Dose ◽  
Absorption Lines ◽  
Ir Absorption ◽  
Absorption Analysis ◽  
Low Carbon ◽  
Dose Irradiation ◽  
Highly Sensitive ◽  
Order Of Magnitude

Complexes formed by low dose irradiation with electron (1015-16/cm2) and He (5x1012- 5x1013/cm2) in the relatively low carbon concentration (1016/cm3) MCZ silicon were investigated by highly sensitive and quantitative IR absorption analysis. CiOi and VO were the main complexes in all cases. The concentration of these complexes was about 1015/cm3, or 10% of included carbon in the highest case. Loss of almost equal amount of Cs was observed. The concentration of CiOiI was one order of magnitude lower. Upon annealing, these lines weakened and almost disappeared at 400 oC. There were some absorption lines introduced by the annealing. VO2 was strongest among them and CsOi related structure was also confirmed. There were absorption lines at 954.9 and 962.6 cm-1 appeared after annealing at 300 oC.

scholarly journals Anharmonicity in the mid-infrared spectra of polycyclic aromatic hydrocarbons: molecular beam spectroscopy and calculations

2019 ◽  
Vol 628 ◽  
pp. A130 ◽  
Author(s):  
A. K. Lemmens ◽  
D. B. Rap ◽  
J. M. M. Thunnissen ◽  
C. J. Mackie ◽  
A. Candian ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Infrared Spectra ◽  
Aromatic Hydrocarbons ◽  
Molecular Beam ◽  
Supersonic Jet ◽  
Ir Absorption ◽  
Mid Infrared ◽  
Out Of Plane ◽  
Polycyclic Aromatic ◽  
Combination Bands

Aims. In this work we determine the effects of anharmonicity on the mid-infrared spectra of the linear polycyclic aromatic hydrocarbons (PAHs) naphthalene, anthracene, tetracene and pentacene recorded using the free electron laser FELIX. Methods. Comparison of experimental spectra obtained under supersonic jet conditions with theoretically predicted spectra was used to show if anharmonicity explicitly needs to be taken into account. Results. Anharmonic spectra obtained using second-order vibrational perturbation theory agree on average within 0.5% of the experimental frequencies. Importantly, they confirm the presence of combination bands with appreciable intensity in the 5–6 μm region. These combination bands contain a significant fraction of the IR absorption, which scales linearly with the size of the PAH. Detection and assignment of the combination bands are a preliminary indication of the accuracy of far-IR modes in our anharmonic theoretical spectra. Detailed analysis of the periphery-sensitive CH out-of-plane band of naphthalene reveals that there is still room for improvement of the VPT2 approach. In addition, the implications of our findings for the analysis of the aromatic infrared bands are discussed.

The Effects of ion Bombardment in Plasma Polymerization

1986 ◽  
Vol 68 ◽  
Author(s):  
Richard J. Buss
Keyword(s):  
Plasma Polymerization ◽  
Molecular Beam ◽  
Vacuum Chamber ◽  
Uv Light ◽  
Film Surface ◽  
Ion Bombardment ◽  
Ir Absorption ◽  
Ir Absorption Spectra ◽  
Plasma Species

AbstractA molecular beam probe technique has been used to investigate the role of ion bombardment of the film surface during the plasma polymeriz-ation process.Thin films have been deposited in a vacuum chamber from a molecular beam containing all the plasma species and these were compared with similar deposits from a beam with the charged particles deflected away.A comparison was made of deposition rates, vis/UV and IR absorption spectra of the films.It was found that the deposition rate was increased 20% with the elimination of ion bombardment.Ions incident on the film surface during deposition cause a net ablation of the film.The ion bombardment also causes an increased absorption of UV and near UV light by the film resulting in a noticeable yellowing.No change was observed in the IR spectra of the films with ion deflection.

Oriented Carbon Pair Defects Stabilized by Hydrogen in as-Grown GaAs Epitaxial Layers

1993 ◽  
Vol 325 ◽  
Author(s):  
Y.M. Cheng ◽  
M. Stavola ◽  
C.R. Abernathy ◽  
S.J. Pearton
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Complex ◽  
Growth Surface ◽  
Ir Absorption ◽  
Carbon Doped ◽  
Growth Plane ◽  
Stretching Vibration ◽  
Metalorganic Molecular Beam Epitaxy ◽  
Series Of Experiments

AbstractWe have studied the IR absorption of heavily carbon doped GaAs grown by metalorganic molecular beam epitaxy. A striking observation is that the hydrogen-stretching vibration of a Crelated complex at 2688 cm−1 is strongly polarized along just one of the <110> directions in the (001) growth plane. This polarized C-H vibration is assigned to a defect complex that is aligned at the growth surface and then maintains its alignment as it is incorporated into the growing crystal. In a series of experiments, we have studied the annealing of the 2688 cm−1 band and its alignment and suggest that the defect complex consists of a CAs-CAs pair stabilized by hydrogen.

Shape and width of IR absorption lines across supersonic free jets

1984 ◽  
Vol 107 (1) ◽  
pp. 31-34 ◽  
Author(s):  
M.A. Gaveau ◽  
D. Boscher ◽  
J.P. Martin
Keyword(s):  
Absorption Lines ◽  
Ir Absorption ◽  
Free Jets

Defects in Heavily-Doped MBE GaAs

1982 ◽  
Vol 40 ◽  
pp. 442-445
Author(s):  
C.B. Carter ◽  
D.M. DeSimone ◽  
T. Griem ◽  
C.E.C. Wood
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Heavily Doped

Molecular-beam epitaxy (MBE) is potentially an extremely valuable tool for growing III-V compounds. The value of the technique results partly from the ease with which controlled layers of precisely determined composition can be grown, and partly from the ability that it provides for growing accurately doped layers.

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