On the polarizabilities of the doubly charged ions of group IIB

Pyper, N.C.; Pike, C.G.; Popelier, P; Edwards, P. P.

doi:10.1080/00268979500102541

Cited by 19 publications

(18 citation statements)

References 45 publications

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“…The bulk polarizability being in the case of MO-type oxide structure, the sum of the anionic and the cationic polarizability, we find aZn(in ZnO) = 9.828~;. This value is surprisingly 3.5 times larger than that for the free Zn2+ ion (2.83~~;) [47]. This close dependence of 3d" or 4d" cations polarizability with their environment has been recently discussed by Pyper et al [47] for Cd2+ and Zn2+.…”

Section: Intermolecular Potential For Adsorptionsupporting

confidence: 52%

“…This value is surprisingly 3.5 times larger than that for the free Zn2+ ion (2.83~~;) [47]. This close dependence of 3d" or 4d" cations polarizability with their environment has been recently discussed by Pyper et al [47] for Cd2+ and Zn2+. These authors have also noted a large increase of the Cd2+ polarizability in CdO as compared with that of the free ion (Cd belongs to the same column as Zn in the Mendeliev table).…”

Section: Intermolecular Potential For Adsorptionmentioning

confidence: 75%

“…These authors have also noted a large increase of the Cd2+ polarizability in CdO as compared with that of the free ion (Cd belongs to the same column as Zn in the Mendeliev table). The origin of such a large value of the dipole polarizability Cd2' in oxide remains however unclear [47]. Note that for the s2 or p6 outermost electronic structure, cation polarizability is found independent of its environment and equals that of the free cation in contrast for anions [43].…”

Section: Intermolecular Potential For Adsorptionmentioning

confidence: 98%

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The adsorption of argon on ZnO at 77 K

1999

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We have studied the adsorption of argon onto ZnO surfaces at 77K by means of quasiequilibrium adsorption volumetry coupled with high resolution microcalorimetry and Grand Canonical Monte-Carlo (GCMC) simulations. The adsorbate/surface adsorption potential function (PN type) used in the simulations, was determined on the basis of ab initio calculations (corrected for dispersion interactions). The first aspect of this work was to test the ability of a standard solid-state Hartree-Fock technique coupled with a perturbative semiempirical approach in deriving a reliable adsorption potential function. The dispersion part of the adsorbate/surface interatomic potential was derived by using perturbation theory-based equations while the repulsive and induction interactions were derived from periodic HartreeFock (CRYSTAL92) calculations. GCMC simulations based on this adsorption potential allow one to calculate adsorption isotherms and isosteric heat versus loading curves as well as singlet distribution functions at 77 K for each type of ZnO (neutral and polar) faces. The combined analysis of the simulation data for all surfaces gives a good insight of the adsorption mechanism of argon onto ZnO surfaces at 77K in agreement with experiment. As far as neutral surfaces are concerned, it is shown that adsorption first takes place within the 'troughs' which cover ZnO neutral surfaces. At low chemical potentials, these semi-channels are preferential adsorption sites in which we could detect a nearly one-dimensional adsorbate freezing in a commensurate phase at 77K. The polar 0 faces are the most favourable surfaces for adsorption at higher chemical potentials.

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Section: Intermolecular Potential For Adsorptionsupporting

confidence: 52%

Section: Intermolecular Potential For Adsorptionmentioning

confidence: 75%

Section: Intermolecular Potential For Adsorptionmentioning

confidence: 98%

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The adsorption of argon on ZnO at 77 K

1999

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“…The additivity rule is, in fact, only approximately valid for ionic compounds (14,16). In these solids, the polarizability of the cation can be assimilated, as a first approximation, to the polarizability of the free cation as given by Pauling (18). However, recent studies have shown that, as soon as the covalency in the solid increases, the additivity rule becomes incorrect and the electronic polarizability of the cation in the solid differs from that of the free ion (18,19).…”

Section: Limitations Of the Classical Methodsmentioning

confidence: 99%

“…In these solids, the polarizability of the cation can be assimilated, as a first approximation, to the polarizability of the free cation as given by Pauling (18). However, recent studies have shown that, as soon as the covalency in the solid increases, the additivity rule becomes incorrect and the electronic polarizability of the cation in the solid differs from that of the free ion (18,19). As shown by Ishara et al in the study of TiO (20), the real electronic polarizability of the cation Ti> in the crystal is higher than that calculated by classical methods (that is, that of the free ion).…”

Section: Limitations Of the Classical Methodsmentioning

confidence: 99%