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Quantum chemical study of Li-, Na- and K-faujasites
vi
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN J. PHYS. CHEM. SOL.
atom. This high effective density of states is consistent with the large effective mass (and low mobility) of electrons in this material. It is shown also that in this range, the temperature dependence of the electronic mobility in VOa is TwY where y > 2. Additional results are discussed in the text. Received 28 Jury 1980 Revised 8 July 1981
20.
ZEROS OF THE TRANSVERSE MAGNETORESISTANCE IN n-TYPE SILICON (100) INVERSION LAYERS H. Kohler and M. Roos, Physikalisches Institut, Universitat Wiirzburg, D-8700 Wiirzburg, F.R.G.
The transverse and Hall resistance are investigated under quantizing electric and magnetic fields in n-type silicon (100) MOSFET inversion layers. The transverse resistance pxx vanishes within finite ranges of the gate voltage where the concentration of channel conduction electrons is constant. The variation of the oscillatory period towards low gate voltages is not compatible with the concept of carrier localization and therefore can be understood by charge transfer into states outside the surface channel.
22.
QUANTUM CHEMICAL STUDY OF Li-, NaAND K-FAUJASITES S. Beran, Chemistry Academy Prague 2,
J. Heyrovsky Institute of Physical and Electrochemistry, Czechoslovak of Sciences, Machova 7, 12 1 38 Czechoslovakia.
The physico-chemical properties of Li-, Na- and K-zeolites modelled by T606(OH)r2 clusters were studied by the CND0/2 method. It was shown that the physical characteristics of the zeolite skeleton (charge density, bond strength, electron structure) are practically independent of the type of cation coordinated in its Srr and S; cation positions. The studied zeolites differ in the cation charge, which has values of about 0.0,0.3 and 0.6 for Li, Na and K, respectively, and in the character of the cation-skeleton bonds in the zeolite, whose ionicity decreases in the order, K > Na > Li. The calculated characteristics of zeolites are employed in the discussion of their interactions with H?O. Received 27 April 198 1 Revised 28 July 1981
THEORY OF THE ANOMALOUS HALL EFFECT IN A SEMICONDUCTOR UNDER UNIAXIAL STRESS H. Biernat, Institut fur Theoretische Universitit Graz, W. Germany.
Physik der
By including spin-orbit dependent contributions, an effective conduction band Hamiltonian for a two band semiconductor is calculated. In doing so we use the band-structure of a sample defomed by uniaxial stress. The equations of motion for position and momentum are calculated employing the effective Hamiltonian. With the help of the Boltzmann equation the magnetization-dependent (anomalous) Hall effect is worked out in the case of uniaxial stress on the sample. Received 25 March 1981
23.
DIFFUSION ET ROTATION DU FLUOR DANS UN FLUORURE IONIQUE: ETUDE PAR R.M.N. DE Ba4_xZr2+x,2 F r6 Jean Senegas, Laboratoire de Chimie du Solide du CNRS, Universitt! de Bordeaux I, 351, tours de la Liberation, 33405 Talence Cedex, France; and Jean-Paul Laval et Bernard Frit , Laboratoire de Chimie Minerale Structurale, U.E.R. des Sciences de Limoges, 123, rue Albert Thomas, 87060 Limoges, France.
Received 6 May 1981
21.
Vol. 41, No. 5
Fluoride subcell thermal behavior has been studied from 180 to 450 K for two compositions Ba4_rZr2+,..2F16 corresponding tox = 0.04 and x = 0.26. At low temperature two fluorine atoms rotate quickly around a baryum atom. Above 330 K this phenomenon leads diffusion thanks to an exchange mechanism between the previous fluorine atoms and the others, the whole anionic subcell being then affected by the fluorine mobility. Activation energy decreases from 0.52 to 0.46 eV asx increases from 0.04 to 0.22. This property seems to be closely related to the formation of cationic vacancies whose number increases with x. Received 11 May 1981 Revised 7 July 1981
24.
DOPING MECHANISM OF A SEMI-CONDUCTING POLYMER: IODINE-DOPED POLYACETYLENE J.P. Louboutin and F. Beniere, Departement de Physique Cristalline, Universitd de Rennes I, Avenue du General Leclerc, 35042 Rennes Cedex, France.
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN J. PHYS. CHEM. SOL.
atom. This high effective density of states is consistent with the large effective mass (and low mobility) of electrons in this material. It is shown also that in this range, the temperature dependence of the electronic mobility in VOa is TwY where y > 2. Additional results are discussed in the text. Received 28 Jury 1980 Revised 8 July 1981
20.
ZEROS OF THE TRANSVERSE MAGNETORESISTANCE IN n-TYPE SILICON (100) INVERSION LAYERS H. Kohler and M. Roos, Physikalisches Institut, Universitat Wiirzburg, D-8700 Wiirzburg, F.R.G.
The transverse and Hall resistance are investigated under quantizing electric and magnetic fields in n-type silicon (100) MOSFET inversion layers. The transverse resistance pxx vanishes within finite ranges of the gate voltage where the concentration of channel conduction electrons is constant. The variation of the oscillatory period towards low gate voltages is not compatible with the concept of carrier localization and therefore can be understood by charge transfer into states outside the surface channel.
22.
QUANTUM CHEMICAL STUDY OF Li-, NaAND K-FAUJASITES S. Beran, Chemistry Academy Prague 2,
J. Heyrovsky Institute of Physical and Electrochemistry, Czechoslovak of Sciences, Machova 7, 12 1 38 Czechoslovakia.
The physico-chemical properties of Li-, Na- and K-zeolites modelled by T606(OH)r2 clusters were studied by the CND0/2 method. It was shown that the physical characteristics of the zeolite skeleton (charge density, bond strength, electron structure) are practically independent of the type of cation coordinated in its Srr and S; cation positions. The studied zeolites differ in the cation charge, which has values of about 0.0,0.3 and 0.6 for Li, Na and K, respectively, and in the character of the cation-skeleton bonds in the zeolite, whose ionicity decreases in the order, K > Na > Li. The calculated characteristics of zeolites are employed in the discussion of their interactions with H?O. Received 27 April 198 1 Revised 28 July 1981
THEORY OF THE ANOMALOUS HALL EFFECT IN A SEMICONDUCTOR UNDER UNIAXIAL STRESS H. Biernat, Institut fur Theoretische Universitit Graz, W. Germany.
Physik der
By including spin-orbit dependent contributions, an effective conduction band Hamiltonian for a two band semiconductor is calculated. In doing so we use the band-structure of a sample defomed by uniaxial stress. The equations of motion for position and momentum are calculated employing the effective Hamiltonian. With the help of the Boltzmann equation the magnetization-dependent (anomalous) Hall effect is worked out in the case of uniaxial stress on the sample. Received 25 March 1981
23.
DIFFUSION ET ROTATION DU FLUOR DANS UN FLUORURE IONIQUE: ETUDE PAR R.M.N. DE Ba4_xZr2+x,2 F r6 Jean Senegas, Laboratoire de Chimie du Solide du CNRS, Universitt! de Bordeaux I, 351, tours de la Liberation, 33405 Talence Cedex, France; and Jean-Paul Laval et Bernard Frit , Laboratoire de Chimie Minerale Structurale, U.E.R. des Sciences de Limoges, 123, rue Albert Thomas, 87060 Limoges, France.
Received 6 May 1981
21.
Vol. 41, No. 5
Fluoride subcell thermal behavior has been studied from 180 to 450 K for two compositions Ba4_rZr2+,..2F16 corresponding tox = 0.04 and x = 0.26. At low temperature two fluorine atoms rotate quickly around a baryum atom. Above 330 K this phenomenon leads diffusion thanks to an exchange mechanism between the previous fluorine atoms and the others, the whole anionic subcell being then affected by the fluorine mobility. Activation energy decreases from 0.52 to 0.46 eV asx increases from 0.04 to 0.22. This property seems to be closely related to the formation of cationic vacancies whose number increases with x. Received 11 May 1981 Revised 7 July 1981
24.
DOPING MECHANISM OF A SEMI-CONDUCTING POLYMER: IODINE-DOPED POLYACETYLENE J.P. Louboutin and F. Beniere, Departement de Physique Cristalline, Universitd de Rennes I, Avenue du General Leclerc, 35042 Rennes Cedex, France.