TY  - JOUR
A1  - Tacke, M.
A1  - Schuberth, W.
A1  - Becker, Charles R.
A1  - Haas, L. D.
T1  - The dielectric constant of PbTe at 4.2 K and \(\tilde ν\)=84.15 cm\(^{-1}\), 96.97 cm\(^{-1}\), 103.60 cm\(^{-1}\)
N2  - The dielectric constant of a PbTe epitaxial layer has been measured by surface wave spectroscopy using an optically pumped far-infrared laser and the technique of attenuated total reflection.
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30821
ER  - 
TY  - JOUR
A1  - Geis, G.
A1  - Geick, R.
A1  - Becker, Charles R.
A1  - Wagner, V.
T1  - Antiferromagnetic resonance in CoO/NiO mixed crystals
N2  - We have studied the lowest magnetic excitation of Ni\(_{1-x}\)Co\(_x\)O mixed crystals for 0.94 \(\leq\) x \(\leq\) 1. Together with previous results for 0.02 \(\leq\) x \(\leq\) 0.07 and neutron data for x = 0.14 and x = 0.30, the results are discussed by means of a model, especially the variation of AFMR frequency and preferred spin direction with Co concentration x.
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31239
ER  - 
TY  - JOUR
A1  - Becker, Charles R.
T1  - Impurity-induced absorption in or near the phonon gap of KI
N2  - In or near the phonon gap of KI a single weak line due to OW (OD\(^-\)) at 69.7 (69.3) cm\(^{-1}\) has been observed. A second and much stronger line at 94.1 cm\(^{-1}\) was shown not to be related to OH\(^-\), but instead is thought to be due to CO\(_3\).
Y1  - 1970
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30757
ER  - 
TY  - JOUR
A1  - Köhler, H.
A1  - Becker, Charles R.
T1  - Optically active lattice vibrations in Bi\(_2\)Se\(_3\)
N2  - The preparation of Bi2Sea single crystals with low free carrier densities allowed an investigation of the lattice vibrations to be carried out from the reflectivity of cleavage planes at nearly normal incidence of the radiation (E ~ c). The experimental results ean be explained with two classical oscillators, whose eigenfrequencies oceur at 92 and 69.5 cm-I. The static dielectric constant was determined to be 100 ± 10 for E ~ c.
N2  - Die Praparation von Bi2Se3-Einkristallen mit niedriger Konzentration freier Ladungstrager erlaubte die Untersllchung der Gitterschwingungcn aus dem Reflexionsvermogen von Spaltflaclwn bci nahezu senkreehter Inzidenz der Stmhlung (E ~ c). Die .:\'IeBergebnisse konnen mit zwei klassischen Dispersionsoszillatoren erklart werden, deren Eigenfrequenzen bei 92 und 69,5 cm- I liegen. Dic st,atische Dielektrizitatskonstante wurde zu 100 ± 10 für E ~ c bestimmt.
Y1  - 1974
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31296
ER  - 
TY  - JOUR
A1  - Klitzing, K. von
A1  - Becker, Charles R.
T1  - Far infrared photoconductivity of residual acceptors in pure tellurium
N2  - The photoconductivity of both undeformed and deformed Te samples has been investigated at liquid He temperature by means of a Fourier spectrometer. Three peaks were usually found in the spectra of undeformed samples at 11, 24 and 46 cm\(^{-1}\). These are shown to be due to three different chemical impurities. The deformed samples are characterized by additional structure at higher frequencies.
Y1  - 1976
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31278
ER  - 
TY  - JOUR
A1  - Becker, Charles R.
T1  - Evidence for a quasi-phonon gap in CsCl
N2  - The observed impurity induced far-infrared absorption in CsCl : Rb\(^+\) and CsCl : K\(^+\) is compared with a calculated density of acoustic phonon states in CsCl. The absorption due to CsCl : Rb\(^+\) displays a minimum between the acoustic and optic phonon bands. A narrow line is observed in CsCl: K\(^+\) at 85.8 cm\(^{-1}\) which falls in this quasi-phonon gap.
Y1  - 1971
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30767
ER  - 
TY  - JOUR
A1  - Schubert, D.W.
A1  - Kraus, M.M
A1  - Kenklies, R.
A1  - Becker, Charles R.
A1  - Bicknell-Tassius, R.N.
T1  - Composition and wavelength dependence of the refractive index in Cd\(_{1-x}\)Mn\(_x\)Te epitaxial layers
N2  - We have investigated Cd\(_{1-x}\)Mn\(_x\)Te thin films with Mn concentrations of x=0.12, 0.18, 0.30, 0.52, and 0.70. These single crystal layers were grown by molecular beam epitaxy on [001] CdTe substrates. The real part of the refractive index, n, was determined below the band-gap Eo in the range of 0.5-2.5 eV at T=300 K. The parallel reOectivity was measured near the Brewster angle at the YAG laser wavelength of 1.064 J.Lm (hv= 1.165 eV). Combining these results with the optical pathlength results (nd) of reOection measurements in a Fourier spectrometer we have determined n(x,v) over a wide spectral range by utilizing a three parameter fit. The accuracy of these results for n should improve waveguide designs based on this material.
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-37716
ER  - 
TY  - JOUR
A1  - Wu, Y. S.
A1  - Becker, Charles R.
A1  - Waag, A.
A1  - Bicknell-Tassius, R. N.
A1  - Landwehr, G.
T1  - The effects of laser illumination and high energy electrons on molecular-beam epitaxial growth of CdTe
N2  - We report the results of a detailed investigation on the Te-stabilized (2 x 1) and the Cdstabilized c( 2 X 2) surfaces of ( 100) CdTe substrates. The investigation demonstrates for the first time that both laser illumination and, to a greater extent, high-energy electron irradiation increase the Te desorption and reduce the Cd desorption from ( 100) CdTe surfaces. Thus it is possible by choosing the proper growth temperature and photon or electron fluxes to change the surface reconstruction from the normally Te-stabilized to a Cd-stabilized phase.
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30795
ER  - 
TY  - JOUR
A1  - Becker, Charles R.
A1  - Wu, Y. S.
A1  - Waag, A.
A1  - Kraus, M. M.
A1  - Landwehr, G.
T1  - The orientation independence of the CdTe-HgTe valence band offset as determined by x-ray photoelectron spectroscopy
N2  - No abstract available
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30784
ER  - 
TY  - JOUR
A1  - Becker, Charles R.
A1  - Lau, Ph.
A1  - GEICK, R.
A1  - Wagner, V.
T1  - Antiferromagnetic Resonance in NiO:Co\(^{2+}\) and NiO:Fe\(^{2+}\)
N2  - No abstract available.
Y1  - 1975
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30772
ER  -