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Spectra of synthetic zeolites containing transition metal ions - III. A simple model calculation of the system adsorbed molecule — NiA zeolite
Vol. 7, No. 12 13.
ABSTRACTS OF PAPERS TO APPEAR IN
MODEL BAND STRUCTURES IN NON LINEAR OPTICS K.C. Rustagi (Tata Institute of Fundamental Research, Bombay, India) Calculation of linear and nonlinear optical
susceptibilities is considered in the band theory formulation. A simple two band model is found 3~the to be and useful the discussion of x’ respectively and x first thirdinorder susceptibilities and unsuitable for a description of the second order susceptibility >~2. The restrictions placed on the two band and three band.models by the general results of band theory are discussed and the role of space inversion symmetry is assessed. It is shown that Kane’s model for the band structure of small gap Ill—V compounds provides a suitable basis for a discussion of >~2. Proper inclusion of the spin orbit coupling is found to be crucial for this purpose, and a direct relationship between the k-linear terms in the valence bands and x2 is established in this model. The agreement of rough estimates of the magnitudes of the k-linear terms based on the observed values of x2 with Dresseihaus’ estimate of these terms seems to support our basic assumptions. It is apparent from our results that a refined calculation of the imaginary part of >~2 and its comparison with the suggested experiments will yield quantitative determination of parameters depending directly on the inversion asymmetric part of the crystal potential. (Received 17 September 1968)
14.
V
Adsorption on NiA zeolite sites where the Ni2 + ions are surrounded by the neighboring ligands of the D 3h symmetry is treated as a transition to C3.. symmetry whereby the adsorbed molecule represents a perturbation whose ligand field strength is expressed as a function of variable parameters. The main feature of the corresponding spectral changes, namely a bathochromicleading shift of to thea change main band in thefrom visible region, of color yellow to pinklow during adsorption, andqualitatively a band separation in the energy region, are explained by this model. (Received 28 February 1969)
15.
THE FREQUENCY AND TEMPERATURE DEPENDENCE OF THE OPTICAL EFFECTIVE MASS OF CONDUCTION ELECTRONS IN SIMPLE METALS Chian-Yuan Young (Department of Physics, University of California, San Diego, La Jolla, California 92037)
In the infrared frequency regime, renormalization effects of conduction electrons in a simple metal alters the frequency and temperature dependence of the conductivity. This change in conductivity can be described by a frequency and temperature dependent effective mass. The case of aluminum has been calculated as an example. The results obtained indicate that measurements of the infrared optical constants as functions of the frequency and temperature can be used to study the variation of the optical effective mass.
SPECTRA OF SYNTHETIC ZEOLITES CONTAINING TRANSITION METAL IONS — III. A SIMPLE MODEL CALCULATION OF THE SYSTEM ADSORBED MOLECULE — NiA ZEOLITE R. Polék and K. Klier (Institute of Physical Chemistry, Czechoslovak Academy of Sciences, Prague, Czechoslovakia, and Center for Surface and Coatings Research, Lehigh University, Bethlehem, Pa 18015, USA)
J. PHYS. CHEM. SOLIDS
(Received 4 March 1969)
16.
STRUCTURE MAGNETIQUE A TROIS SOUS-RESEAUX DANS L’APPROXIMATION DU CHAMP MOLECULAIRE B. Boucher, R. Buhi and M. Perrin (Service de Physique du Solide et de Resonance Magnétique Centre d’Etudes Nucléaires de Saclay BP n°2—91, Gifsur-Yvette, France)
ABSTRACTS OF PAPERS TO APPEAR IN
MODEL BAND STRUCTURES IN NON LINEAR OPTICS K.C. Rustagi (Tata Institute of Fundamental Research, Bombay, India) Calculation of linear and nonlinear optical
susceptibilities is considered in the band theory formulation. A simple two band model is found 3~the to be and useful the discussion of x’ respectively and x first thirdinorder susceptibilities and unsuitable for a description of the second order susceptibility >~2. The restrictions placed on the two band and three band.models by the general results of band theory are discussed and the role of space inversion symmetry is assessed. It is shown that Kane’s model for the band structure of small gap Ill—V compounds provides a suitable basis for a discussion of >~2. Proper inclusion of the spin orbit coupling is found to be crucial for this purpose, and a direct relationship between the k-linear terms in the valence bands and x2 is established in this model. The agreement of rough estimates of the magnitudes of the k-linear terms based on the observed values of x2 with Dresseihaus’ estimate of these terms seems to support our basic assumptions. It is apparent from our results that a refined calculation of the imaginary part of >~2 and its comparison with the suggested experiments will yield quantitative determination of parameters depending directly on the inversion asymmetric part of the crystal potential. (Received 17 September 1968)
14.
V
Adsorption on NiA zeolite sites where the Ni2 + ions are surrounded by the neighboring ligands of the D 3h symmetry is treated as a transition to C3.. symmetry whereby the adsorbed molecule represents a perturbation whose ligand field strength is expressed as a function of variable parameters. The main feature of the corresponding spectral changes, namely a bathochromicleading shift of to thea change main band in thefrom visible region, of color yellow to pinklow during adsorption, andqualitatively a band separation in the energy region, are explained by this model. (Received 28 February 1969)
15.
THE FREQUENCY AND TEMPERATURE DEPENDENCE OF THE OPTICAL EFFECTIVE MASS OF CONDUCTION ELECTRONS IN SIMPLE METALS Chian-Yuan Young (Department of Physics, University of California, San Diego, La Jolla, California 92037)
In the infrared frequency regime, renormalization effects of conduction electrons in a simple metal alters the frequency and temperature dependence of the conductivity. This change in conductivity can be described by a frequency and temperature dependent effective mass. The case of aluminum has been calculated as an example. The results obtained indicate that measurements of the infrared optical constants as functions of the frequency and temperature can be used to study the variation of the optical effective mass.
SPECTRA OF SYNTHETIC ZEOLITES CONTAINING TRANSITION METAL IONS — III. A SIMPLE MODEL CALCULATION OF THE SYSTEM ADSORBED MOLECULE — NiA ZEOLITE R. Polék and K. Klier (Institute of Physical Chemistry, Czechoslovak Academy of Sciences, Prague, Czechoslovakia, and Center for Surface and Coatings Research, Lehigh University, Bethlehem, Pa 18015, USA)
J. PHYS. CHEM. SOLIDS
(Received 4 March 1969)
16.
STRUCTURE MAGNETIQUE A TROIS SOUS-RESEAUX DANS L’APPROXIMATION DU CHAMP MOLECULAIRE B. Boucher, R. Buhi and M. Perrin (Service de Physique du Solide et de Resonance Magnétique Centre d’Etudes Nucléaires de Saclay BP n°2—91, Gifsur-Yvette, France)