Far-infrared absorption in bulk samples of superconducting niobium and tantalum

1970 ◽  
Vol 48 (10) ◽  
pp. 1254-1258 ◽  
Author(s):  
D. Hemming ◽  
R. Sati ◽  
J. D. Leslie
Keyword(s):  
Critical Temperature ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Gap Width ◽  
Absorption Measurements ◽  
Good Agreement

Measurements have been made of far-infrared absorption in bulk samples of superconducting niobium and tantalum at 1.41 °K. The results indicate a gap width 2Δ of 23.8 ± 0.2 cm−1 for niobium and 10.3 ± 0.2 cm−1 for tantalum. The measured values of the critical temperature, Tc, for these samples are 9.38 ± 0.04 °K for niobium and 4.33 ± 0.02 °K for tantalum. In terms of these values of Tc, 2Δ is 3.66 ± 0.05 kTc for niobium and 3.43 ± 0.08 kTc for tantalum. These values of 2Δ are in good agreement with those obtained by other methods, unlike earlier far-infrared absorption measurements on bulk niobium and tantalum that indicated anomalously low values of 2Δ.

Far-Infrared Absorption in Bulk Samples of Superconducting d-h.c.p. Lanthanum

1972 ◽  
Vol 50 (20) ◽  
pp. 2549-2551
Author(s):  
L. W. Kry ◽  
D. Hemming
Keyword(s):  
Infrared Absorption ◽  
Far Infrared ◽  
A Value ◽  
Gap Width ◽  
Absorption Measurements

Far-infrared absorption measurements have been made on bulk samples of d-h.c.p. lanthanum and the results indicate a gap width, 2Δ, of 11.6 ± 0.3 cm−1 or 1.44 ± 0.04 meV. Using a value of Tc = 4.87 ± 0.02 °K, taken from the literature, this gives 2Δ = (3.43 ± 0.09)kTc.

High-pressure far-infrared absorption measurements on La1−xCaxMnO3−δ by means of synchrotron radiation

2006 ◽  
Vol 49 (1-2) ◽  
pp. 92-95
Author(s):  
A. Sacchetti ◽  
M. Cestelli Guidi ◽  
E. Arcangeletti ◽  
P. Postorino ◽  
A. Nucara ◽  
...  
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Absorption Measurements

Far-Infrared Absorption Measurements of Polypeptides and Cytochromecby THz Radiation

2002 ◽  
Vol 75 (5) ◽  
pp. 1083-1092 ◽  
Author(s):  
Kohji Yamamoto ◽  
Keisuke Tominaga ◽  
Hiroaki Sasakawa ◽  
Atsuo Tamura ◽  
Hidetoshi Murakami ◽  
...  
Keyword(s):  
Infrared Absorption ◽  
Far Infrared ◽  
Thz Radiation ◽  
Absorption Measurements

Local and Electronic Structure of Siloxene

1999 ◽  
Vol 14 (4) ◽  
pp. 1235-1237 ◽  
Author(s):  
Ernst Z. Kurmaev ◽  
Sergei N. Shamin ◽  
David L. Ederer ◽  
Ursula Dettlaff-Weglikowska ◽  
Jörg Weber
Keyword(s):  
Electronic Structure ◽  
Infrared Absorption ◽  
Emission Spectra ◽  
Close Similarity ◽  
X Ray ◽  
Powder Samples ◽  
Absorption Measurements ◽  
Good Agreement ◽  
Oxygen Atoms

Silicon L2,3 x-ray emission spectra (XES) of siloxene powder samples prepared according to Wöohler and Kautsky (Wöhler and Kautsky siloxene) are presented. The results are compared with the Si L2,3 spectra of the reference compounds a-Si, c-Si, SiO2, and SiOx. A close similarity of the electronic structure of Wöhler siloxene to that of a-SiO0.43: H and of Kautsky siloxene to that of a-SiO0.87: H is found. We determine the number of oxygen atoms per Si atom at ~0.5 in Wöhler siloxene and ~0.8 in Kautsky siloxene. The relative concentrations are in good agreement with the results of infrared absorption measurements on the same samples.

Temperature and Frequency Dependence of the Infrared Absorption in Three Kinds of Bi-Based Compounds

1992 ◽  
Vol 275 ◽  
Author(s):  
Y. Hayashi ◽  
Y. Harada ◽  
H. Sasakura ◽  
M. Nagayama
Keyword(s):  
Absorption Band ◽  
Infrared Absorption ◽  
Far Infrared ◽  
Infrared Region ◽  
Free Carrier Absorption ◽  
Phonon Modes ◽  
Superconducting Compounds ◽  
Carrier Absorption ◽  
Absorption Measurements ◽  
Made In

ABSTRACTInfrared absorption measurements have been made in three kinds of Bi compounds of a high-Tc family mainly by making use of powdered samples. Two of them are superconductors with Tc's of 108 K and 82 K, respectively, and the remaining one is a semiconductor. In each of the superconducting compounds, there appears Mid-Infrared absorption band: No such absorption band is found in the semiconducting compound. At Far-Infrared region, many absorption peaks due to phonons are clearly detected in all of these samples. Some of the phonon modes have been identified. At very low energy region, free carrier absorption appears in superconductors. Only this part of the absorption shows a temperature dependence. Absorption intensity decreases as the temperature decreases.

Photoluminescence and Infrared Absorption Study of Isoelectronic Impurity Passivation by Hydrogen

2002 ◽  
Vol 719 ◽  
Author(s):  
M. Capizzi ◽  
A. Polimeni ◽  
G. Baldassarri Högher von Höghersthal ◽  
M. Bissiri ◽  
A.Amore Bonapasta ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Thermal Annealing ◽  
Infrared Absorption ◽  
Vibrational Frequencies ◽  
Red Shift ◽  
Absorption Study ◽  
Theoretical Methods ◽  
Absorption Measurements ◽  
Good Agreement

AbstractThe effects of H irradiation and thermal annealing on the optical properties of (InGa)(AsN) heterostructures have been investigated by photoluminescence (PL) and infrared absorption, as well as by theoretical methods. It has been found that different N clusters contribute to the band gap red-shift reported for (InGa)(AsN) alloys, with a sizable localization of the carrier wavefunctions around N atoms. Infrared absorption measurements indicate that two different NH complexes are formed, whose vibrational frequencies are in good agreement with theoretical estimates. The ability of hydrogen to passivate different isoelectronic impurities is confirmed by PL results in H irradiated Zn(STe).

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