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1.
The absorption and MCD spectra of the , , and spin-allowed transitions of Cr3+ in K2NaGaF6 are reported. It is shown that transitions to the . states are induced by T1u vibratio the other spin-allowed transition, , there are three competing intensity mechanisms: electric dipole induced by T1u vibrations, electric dipole induced by T2u vibrations and magnetic dipole, and an estimate is made of the relative importance of these. The magnetic dipole zero-phonon line is observed to be accompanied by a vibrational sideband for which the coupling is predominantly with T2u vibrations. Other weak transitions are observed in MCD spectra and their origin briefly discussed. 相似文献
2.
Metastable He2 molecules are produced by a dc discharge in a flowing He stream. Laser excitation downstream of the discharge produces excitation spectra for a number of He2 states. LIF spectra are observed for the series for n = 4–9, excepting 5 and the series for n = 5–15. 相似文献
3.
Energy curves and transition moments of the excited valence states of Hg2 were obtained in a model calculation based on calculated Mg2 energy levels and the assumption that the asymptotic spin-orbit matrix elements for the Hg atom are applicable to the molecular states. The spin-orbit and orbital-rotational interaction of the excited states of Hg2 is analyzed in both a Hund's case (c) and (a) representation. The intermediate (a) → (c) transition moments are obtained as a function of the internuclear distance. The effect of the orbital-rotational interaction which introduces Hund's case (b) and (e) couplings is found to be small for transitions among excited states under the conditions normally encountered for populating excimer states.Using the energy level positions and transition moments, the observed spectra and predicted spectra are compared for both radiative transitions including the ground state and among the excited states. The lifetime of the excimer state is calculated to be 1.4 μsec with the 335 nm band assigned to the transition. The 485 nm bands cannot be assigned to any Hg2 transitions. Strong bound-continuum absorptions are predicted for the 485 nm bands. On the other hand, the 335 nm emission is predicted to be absorbed by bound-bound transitions only. 相似文献
4.
N.B. Manson 《Solid State Communications》1976,18(2):257-260
Magnetic circular dichroism (MCD) and magnetic linear dichroism (MLD) measurements of the absorption band in MgO:Ni2+ are reported. It is shown that for the lowest energy vibrational peak there is considerable evidence of splitting of the T2g × T1u vibronic levels by the electron-vibration interaction. 相似文献
5.
The (0,0) band of the emission (Infrared Afterglow) system of molecular nitrogen has been recorded with a resolution of 0.046 cm?1 and a line position accuracy of 0.007 cm?1. Six hundred and seventy-two lines are tabulated into a line list for the 1.53 μm (low-resolution) emission feature. Of these, 482 are assigned as members of the 27 branches of the B′ → B transition, while 150 are identified with the 1PG (3,6) band. Molecular constants for the v = 0 levels of the and B3Πg states have been computed and tabulated. 相似文献
6.
Optical absorption spectra of Ni2+ in (NH4)2Mg(SO4)2·6H2O and Co2+ in Na2Zn(SO4)2·4H2O single crystals have been studied at room and liquid nitrogen temperatures. From the nature and position of the observed bands, a successful interpretation could be made assuming octahedral symmetry for both the ions in the crystals. The splitting observed for band in Ni2+ and band in Co2+ at liquid nitrogen temperature have been explained as due to spin-orbit interaction. The extra band observed at 16,325 cm-1 in the case of Ni2+ at low temperature has been interpreted to be the superposition of vibrational mode of SO2-4 radical on band. The observed band positions in both the crystals have been fitted with four parameters B, C, Dq and ζ. 相似文献
7.
C.V.K. Baba D.B. Fossan T. Faestermann F. Feilitzsch P. Kienle C. Signorini 《Physics letters. [Part B]》1973,43(6):483-486
The difference in g-factors for the 61+ and 81+ states in 210Po has been measured as . This result represents a small violation of additivity. A value of g8 = 0.909 ± 0.011, independent of g6, was also obtained. 相似文献
8.
A theoretical model used to describe the and B3Πg states of N2 is presented. Using recently acquired high resolution spectra of the (0-0) band, rotational energy levels of the v = 0 vibrational levels of these two states are generated with this model. These levels are in excellent agreement with those obtained using a combination differences technique. The precision of the model generated levels is 0.01 cm?1. The previously unpublished rotational levels of Dieke and Heath for the , B3Πg and C3Πu states are referenced to the (v = 0, J = 0) ground level and tabulated here. Estimates of the precision of their work are made. 相似文献
9.
D.L. Albritton W.J. Harrop A.L. Schmeltekopf R.N. Zare 《Journal of Molecular Spectroscopy》1973,46(1):103-118
The discrepancies concerning the optical and microwave values of B0 and D0 for the X state of O2 have been removed by a nonlinear least-squares fit to all of the lines of the O2, Red Atmospheric bands recorded by Babcock and Herzberg (Astrophys. J., 108, 167, 1948). The resulting values for B0″ and D0″ are in excellent agreement with the Raman and microwave values. Improved values are determined for B1″, D1″, γ1″ (spin-rotation), and ?1″ (spin-spin). Both γv″ and ?v″ increase in magnitude from v″ = 0 to v″ = 1. Improved Dunham Yi0 and Yi1 expansion coefficients are determined for the state, from which the Rydberg-Klein-Rees potential is constructed. 相似文献
10.
The emission of Ni2+ ions in MgO, KMgF3, KZnF3 and MgF2 crystals has been investigated. The fine structure on the bands at about 20 000 cm-1 and 13 000 cm-1 has been studied in detail and from this and the excitation spectra these bands are assigned to and transitions respectively. 相似文献
11.
H. Englisch 《Reports on Mathematical Physics》1980,18(3):387-397
With the help of Mc Bryan's method we prove the existence of F(?)2-fields, where is a power series with fast decreasing coefficients. Hypercontractive estimates show the existence of fields with a superposition of exponential or cosine functions as interaction, similar to Mc Bryan's interaction. 相似文献
12.
B. Jimenez C. Alemany J. Mendiola E. Maurer 《Journal of Physics and Chemistry of Solids》1985,46(12):1383-1386
The ferro-paraelectric transition in Sr0.5Ba0.5Nb2O6 ceramics has been studied by measuring the dielectric pennitivity as a function of temperature at different frequencies. Experimental results in the transition region over ?'max fit the relation with γ > 1, as is typical for dif transitions. In an interval of temperatures of 17°C over T0 (=Tfor?'max), γ = 2. Using the relaxors' model of Kirillov-Isupov an equation is inferred in order to compute the activation energy of the relaxors as a function of parameters directly obtained from the experimental results. 相似文献
13.
Jon T. Hougen 《Journal of Molecular Spectroscopy》1984,106(1):134-154
Rotational energy levels in vibronic ground states of 2A, 2E, and 2F electronic states of open-shell XY4 molecules, as well as rotational line intensities for allowed transitions between such states, are discussed, including the effects of spin-orbit interaction and tetrahedral splittings. Jahn-Teller effects are assumed to be small, and are only taken into account implicitly, through their contributions to various parameters in the effective Hamiltonian. Qualitative information is obtained by considering several limiting-case coupling schemes among the electron spin angular momentum S, the electron orbital angular momentum L, and the pure rotational angular momentum R. These limiting cases are similar in spirit to Hund's coupling cases in diatomic molecules, but differ sufficiently from the latter to make detailed correspondences unhelpful. Quantitative information on rotational energy levels and line intensities is obtained numerically by diagonalizing a Hamiltonian matrix set up in a basis set characterized by uncoupled moleculefixed projections of S, L, and the total angular momentum J, and symmetrized so that all basis set functions belong to a definite species in the subgroup D2d of the true point group Td. Hamiltonian matrix elements are determined by ladder operator techniques. Three sample calculated spectra, corresponding to , , and are presented. As one might expect, when the spin-orbit constant A is set equal to zero, then both qualitative and quantitative aspects of the rotational-electronic problem in open-shell XY4 molecules can be mapped easily onto discussions of the rotation-vibration problem from the CH4 literature. 相似文献
14.
The 2Πu-X2Πg transition in Br2+ was reexamined using dispersed laser-induced fluorescence, and emission spectroscopy in a seeded molecular beam. New constants are derived, confirming the large difference between and , and reconciling the emission spectrum with photoelectron data. 相似文献
15.
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
16.
Keu Hong Kim Jong Ho Jun Jae Shi Choi 《Journal of Physics and Chemistry of Solids》1985,46(10):1173-1178
The electrical conductivity of the system Y2O3CeO2 was measured in the temperature range 500–1100°C and Po2 range 10–7?10?1 atm. Possible defect models were suggested on the basis of conductivity data, which were investigated as a function of temperature and of Po2. The observed activation energies were 0.40 eV and 1.79 eV in the low- and high-temperature regions, respectively. The observed conductivity dependences on Po2 were in the temperature range 500–750°C and at temperatures from 750–1100°C. It is suggested that the system Y2O3CeO2 shows a mixed ionic plus hole conduction due to an O″i defect and an electronic hole conduction due to a V'''Y defect in the low- and high-temperature regions, respectively. 相似文献
17.
Emission spectra for the electronic transitions , , , , , , , and of 4He2 are reported and the electronic structure of the triplet states associated with v = 0 of (1σg)2(1σu) nsσ and ndλ characterized. The energy levels comprising the and the manifolds exhibit strong channel mixing, while the mixing of the with the channel structure is relatively minor. Models based on multichannel quantum defect theory are used to aid in the spectral assignments and to correlate the observed level structures. We show that three-limit and two-limit models adequately represent the bulk of the observed and channel structures, respectively. 相似文献
18.
A synthetic germanium-doped crystal of α-quartz was subjected to an electro-diffusion process , 625°K), in which Ag+ ions were introduced along the crystal's optic axis (c). A 9800MHz electron paramagnetic resonance spectrum at room temperature, taken after room temperature x-irradiation, revealed the presence of a silver-compensated germanium center AGe?Ag with large, almost isotropic 107Ag and 109Ag hyperfine splittings (26.078, 30.112 mT for magnetic field B∥c). Measurement of the spin-Hamiltonian (i.e. matrices , , and discloses that a suitable model for the observed center utilizes germanium, substituted for silicon, with the accompanying silver interstitial in a nearby c-axis channel, and with electronic structure in which an appreciable admixture Ge4+?Ag0 to Ge3+?Ag+ exists. Estimates of the unpaired electron orbital are presented. 相似文献
19.
EPR of 61Ni+ doped CuGaS2 at 4.2 K leads to the following experimental data: . High axial field splitting of 2T2 state stabilizes the center against Jahn-Teller interaction. Covalency reduction factor k is 0.76. 相似文献
20.
We study lattice g0φ4 field theory for all g0 and fixed renormalized mass M in one and two dimensions using Monte Carlo techniques. We calculate the dimensionless renormalized coupling constant is the dimension of space—time, at fixed small values of the lattice spacing a for various g0 and lattice sizes. Our results are in quantitative agreement with the analyses of high temperature and strong coupling series which rely on extrapolation from large to small lattice spacing. 相似文献