共查询到20条相似文献,搜索用时 62 毫秒
1.
V. Riede H. Neumann H. Sobotta R.D. Tomlinson E. Elliott L. Howarth 《Solid State Communications》1980,33(5):557-559
Infrared reflectivity spectra of p-type CuInTe2 single crystals were measured at room temperature for the polarization direction E ⊥ c and E | c in the wavenumber range from 55 to 4000 cm?1. Fits to a dielectric function including contributions from lattice oscillators and free carriers gave the first determination of the effective hole masses of and . Two optical phonon modes were found for both polarization directions. 相似文献
2.
N.B. Manson J.T. Gourley E.R. Vance D. Sengupta G. Smith 《Journal of Physics and Chemistry of Solids》1976,37(12):1145-1148
At helium temperatures two sharp lines at 9350 and 9510 cm?1 have been observed for the first tune on the low-energy side of the broad double-peaked absorption corresponding to the transition in Fe2+ at the octahedral site in MgO. The lower energy line has a half width of 4 cm?1; Zeeman measurements show that it is of magnetic dipole origin. The Zeeman spectra are consistent with those expected for a pure electronic transition from the (5T2g)T2g ground state to the 5Eg excited state. The second line, with a halfwidth of ~ 35 cm?1, a vibrational sideband. 相似文献
3.
P. Oelhafen M. Liard H.-J. Güntherodt K. Berresheim H.D. Polaschegg 《Solid State Communications》1979,30(10):641-644
The valence bands of glassy and pure Pd were studied by XPS and UPS. The valence band spectra of the alloys show a strongly reduced density of states at the Fermi energy EF compared to Pd. From the measured relative photoelectric cross sections for the different excitation energies we conclude that the electron states near EF of the glassy alloys have mainly d-character. This is in good agreement with recent measurements of the low-temperature specific heat, the magnetic susceptibility and the optical reflectivity. 相似文献
4.
The cyclotron resonance of inversion-layer electrons on (100)p-type Si is found to depend sensitively on an externally applied compressive stress. At low temperatures (T ? 10 K) we observe a considerable increase of the cyclotron mass m1c with stress S along the [001] direction. The effect is most strongly observed at low electron densities ns. For and ns~2 × 1011cm-2 we obtain instead of the expected 0.2m0. Along with this change of a strong narrowing of the resonance is noted. Raising the temperature gives an additional ns- dependent increase of . 相似文献
5.
F. Varret 《Journal of Physics and Chemistry of Solids》1976,37(3):257-263
Pulsed field experiments up to 450 kOe have been performed on FeSiF6.6H2O. We interpret the data: (i) in terms of spin hamiltonian constants: D = 12.3± 0.2 cm-1 (E = 0.54cm-1 being known from EPR data); (ii) in terms of axial-crystal-field parameters: . The magnetic axis is found to deviate from the cristallographie c axis by an angle 1° < θ < 2°. The adiabatic cooling obtained during the pulse is discussed.Similar experiments on Fe0.15Zn0.85SiF6.6H2O and Fe0.30Zn0.70SiF6.6H2O single crystals are reported; in both cases we measure . Using EPR data, we obtain D = 14.3cm-1, λ ~ ?75cm-1, δ ~ 195cm-1; using Mössbauer data, we obtain D = 15.3cm-1, λ ~ ?88cm-1, δ ~ 185cm-1. 相似文献
6.
We report the temperature dependence of the low frequency part (ω < 100 cm?1) of the Raman spectra of the Pb(Ti1-x, Zrx)O3 and , Lax)TiO3 systems. The spectra indicate a coupled mode behavior between the soft E(TO) phonon and a mode which produces an additional band in the spectra. We discuss the possibility that the additional band might be due to zone boundary tranverse acoustical phonons which couple to the q ~ 0 soft E(TO) mode because of the disorder existing in the systems. 相似文献
7.
The coverages of adsorbed oxygen and CO on an Ir(111) surface have been determined using X-ray photoelectron spectroscopy (XPS) during the steady-state catalytic production of CO2. Correlating the coverages of the reacting adsorbates with the rate of CO2 production allows the kinetics of the CO oxidation reaction to be determined. The reaction is found to obey a Langmuir-Hinshelwood rate expression of the form , where RCO2 is the rate of CO2 production, k0 is the pre-exponential factor of the reaction rate coefficient, [CO] and [O] are the surface coverages of CO and oxygen, respectively, and Ea is the activation energy for the oxidation reaction. The activation energy for this catalytic oxidation reaction is found to be approximately 9 . 相似文献
8.
L Nemes 《Journal of Molecular Spectroscopy》1978,72(1):102-123
Medium resolution infrared grating spectra of gaseous ketene, H2CCO were recorded between 1000 and 400 cm?1, both at instrument temperature (40°C) and with cooling (?40°C). Interferometric Fourier spectra were also measured at ?70°C with resolution 0.22 cm?1 between 450 and 330 cm?1. The K structure of the fundamentals ν5, ν6, ν8, and ν9 was assigned. These fundamentals are coupled by a-axis Coriolis interactions. These couplings were analysed on the symmetric top basis for setting up the perturbation matrix and by utilizing the K-dependent Coriolis shifts of levels. A preliminary analysis of the Coriolis intensity anomalies was also undertaken.Band center values from combination differences are and . Synthetic spectra indicate the band origins of ν8 and ν9 to be close to 977.8 and 439.0 cm?1, respectively. Estimates of Coriolis coupling constants obtained from synthetic spectra are , , , and . Approximate ratios of unperturbed vibrational transition moments obtained from spectral simulations are . 相似文献
9.
Kentarou Kawaguchi Chikashi Yamada Yoshiaki Hamada Eizi Hirota 《Journal of Molecular Spectroscopy》1981,86(1):136-142
The fundamental bands of the CF radical in the and electronic states were observed by using an infrared tunable diode laser as a source. Zeeman modulation could be used in detecting lines not only in the state, but also in , because the CF radical deviates considerably from Hund's case (a). From the least-squares analysis of the observed spectra, the following molecular constants were obtained: Be = 1.416 704 (37) cm?1, αe = 0.018 419 (50) cm?1, , De = 6.68 (15) × 10?6cm?1, p0 = 0.008 580 (21) cm?1, p1 = 0.008 52 (11) cm?1, and , with three standard errors in parentheses. 相似文献
10.
M. Tenhover R.S. Henderson D. Lukco M.A. Hazle R.K. Grasselli 《Solid State Communications》1984,51(7):455-459
An analysis of the Raman and Infrared spectra of crystalline and glassy SiSe2 is presented. A tentative assignment of the vibrational modes of crystalline SiSe2 is developed which provides a useful framework for understanding the spectrum of glassy SiSe2. A direct correspondence between the modes of crystalline and glassy SiSe2 is observed that extends not only to modes associated with the elements of short range order tetrahedral units) but also to modes that result from correlated motions of extended units (packets of edge-sharing tetrahedral chains). The present results provide strong evidence for a degree of medium range order greater than that previously proposed for the Si-based glasses. 相似文献
11.
The glass forming tendency and infrared reflectance spectra are investigated in the (Ge, Sn) system. It is found that the glass formation of the SnSe system is much more difficult than that of the Ge system. This is mainly ascribed to the ionicity difference between GeSe and SnSe bonds. Infrared spectra in the glassy Ge1-xSex system at the composition 0.67<x<1.0 indicate the presence of clusters within which the atomic connectivity is similar as in the glassy GeSe2. The vibrational modes caused by the tetrahedron are found in the glassy (Ge, Sn)-Se system. It is suggested that tin atoms are mainly incorporated into the clusters. Importance of the medium range order is discussed in the formation of the glasses. 相似文献
12.
Alan L. Goodman 《Nuclear Physics A》1979,325(1):171-188
Angular momentum is approximately projected from Hartree-Fock-Bogoliubov cranked (HFBC) wave functions. At each J the projected energy is . The spin-dependent fluctuation includes contributions from Jy and Jz as well as Jx. There are no correlations in the three angular momentum components. Projected energies are calculated for 168, 170Yb and 174Hf. When compared to experimental energies, the projected spectra are less compressed than the HFBC spectra. At low spins the projected and experimental energies are in good agreement. 相似文献
13.
The 0-0, 1-1, 2-2, and 3-3 bands of the A2Π-X2Σ+ transition of the tritiated beryllium monohydride molecule have been observed at 5000 Å in emission using a beryllium hollow-cathode discharge in a He + T2 mixture. The rotational analysis of these bands yields the following principal molecular constants. From the pure electronic energy difference (EΠ - EΣ)BeT = 20 037.91 ± 1.5 cm?1 and the corresponding previously known values for BeH and BeD, the following electronic isotope shifts are derived and related to the theoretical approach given by Bunker to the problem of the breakdown of the Born-Oppenheimer approximation. 相似文献
14.
The rotationally resolved, laser-induced fluorescence spectrum of the E band of the transition of SO2 seeded in a supersonic jet was observed, and each rotational line was assigned on the basis of the ground state combination differences and the relative intensity data as a function of the rotational temperature. It was demonstrated that the line congestion was reduced significantly in the spectrum of the jet, and some of the lines, e.g., rR0(0), were assigned unambiguously. This makes it possible to determine the vibronic band origin with an error of less than 0.2 cm?1. 相似文献
15.
Clive E. Barnes John M. Brown Alan D. Fackerell Trevor J. Sears 《Journal of Molecular Spectroscopy》1982,92(2):485-496
Lines in the ν3 (“antisymmetric” stretch) fundamental of the NCO radical in the state were studied by CO laser magnetic resonance. The observations were assigned to P and R lines in the vibration-rotation band and lead to a precise determination of the vibrational interval and the anharmonic correction to the rotational constant: ν3 = 1920.60645(19) cm?1, α3 = 0.003338(21) cm?1. A single transition in the hot band (011)-(010), was detected. This observation is used to determine the origin of the hot band as 1907.11892(20) cm?1, i.e., the anharmonicity parameter x23 = ?13.48753(28) cm?1. 相似文献
16.
Dependence of static dielectric susceptibility and correlation length of charge density waves (CDW) with weak defects on parameter of incommensurability with lattice is investigated. In almost commensurate phase (h?hchc), and Rc ~ (h ? hc). In. Far from commensurability , , where a is the dimensionless ratio of random potential intensities, corresponding to backward and forward scattering impurities. 相似文献
17.
Two new systems of emission bands near 2100 and 3100 Å have been produced by a microwave discharge in B2S3 vapor. From the known X2Σ+ and A2Πi states of BS, these systems have been assigned as E2Σ+ → X2Σ+ and E2Σ+ → A2Πi. Constants in cm?1 for the new state are , 相似文献
18.
The vapor phase absorption spectrum of thiophosgene (Cl2CS) in the 2500–2900 Å region consists of a broad intense band (. On the red side of this a vibrationally discrete structure is found which becomes increasingly diffuse and merges into the broad band as the wavelength is decreased. It is shown that this vibrational structure can be explained as due to a , electronic transition between a planar ground state and a pyramidal excited state of the molecule. In the latter state, the CS stretching mode ν1′(a1) = 681 cm?1 and the CCl bending mode ν3′(a1) = 147 cm?1. From the inversion doublet splitting of the out-of-plane mode ν4′(b1), the barrier to inversion is calculated to be ~126 cm?1, with an equilibrium out-of-plane angle of ~20°. 相似文献
19.
R. Oppermann 《Solid State Communications》1982,44(8):1297-1299
An n-orbital model describing both elastic impurity scattering and exchange interaction is examined near its instability for itinerant ferromagnetism. At the critical point and at zero temperature, long range spin fluctuations cause anomalous enhancements of the density of states near the Fermi energy with in three-dimensions (3D) and with ln2|E ? EF| in 2D. An estimation of the conductivity in a continuum analog model reveals Ω -and ln2-corrections in 3D and 2D respectively. 相似文献
20.
J.C.D. Brand U.D. Deshpande A.R. Hoy S.M. Jaywant 《Journal of Molecular Spectroscopy》1983,100(1):143-150
The E-B (0g+-0u+) band system of Br2 has been investigated at Doppler-limited resolution using polarization labeling spectroscopy. Merged E state data for the three naturally occurring isotopes in the range vE = 0–16, expressed in terms of the constants for 79Br2, are (in cm?1) Y0,0 = 49 777.962(54), Y1,0 = 150.834(22), Y2,0 = ?0.4182(28), Y3,0 = 6.6(11) × 10?4, Y0,1 = 4.1876(28) × 10?2, Y1,1 = ?1.607(16) × 10?4, and Y0,2 = 1.39(39) × 10?8. The bond distance is , and the diabatic dissociation energy to . 相似文献