Effect of three-body forces on Schottky defect energy of alkali halides

Agnihotri, Neeta; Sanyal, Sankar P.; Singh, R. K.

doi:10.1016/0378-4363(86)90215-9

Cited by 6 publications

(8 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The parameters B, f (a) 0 and (a df da ) 0 are determined by using the equilibrium condition (20) and any one of the three elastic constants given by eqs. (5), (6) and (7).…”

Section: Negative Ion Polarizable Model (Nipm)mentioning

confidence: 99%

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

Upadhyaya¹,

Upadhyaya²,

Yadav³

2001

J. Phys. Soc. Jpn.

View full text Add to dashboard Cite

The basic equations of three-body force shell model have been corrected for the ionic charge parameter Z. This correction also modifies the expressions for the shell and core charge parameters. Our model has been applied to study the phonon dispersion curves, Debye temperatures variation, combined density of states and two-phonon Raman scattering spectra of wustite. This approach has been found successful in interpreting the complete lattice dynamics of FeO only when both the ions are considered to be polarizable. There is good scope for the fresh determination of positive ion polarizability and Debye temperatures variation. It is concluded that the presence of magnetic and anharmonic interactions have no effect on the lattice dynamics of FeO in its paramagnetic phase.

show abstract

“…The parameters B, f (a) 0 and (a df da ) 0 are determined by using the equilibrium condition (20) and any one of the three elastic constants given by eqs. (5), (6) and (7).…”

Section: Negative Ion Polarizable Model (Nipm)mentioning

confidence: 99%

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

Upadhyaya¹,

Upadhyaya²,

Yadav³

2001

J. Phys. Soc. Jpn.

View full text Add to dashboard Cite

show abstract

“…A review of the limitations of the two-body potentials in predicting the fundamental defect properties of ionic solids has been reported in a preceding paper [8] from this laboratory. In order to overcome these limitations we have reported a three-body interaction ') Bhopal 462026, India.…”

Section: Introductionmentioning

confidence: 99%

“…In order to overcome these limitations we have reported a three-body interaction ') Bhopal 462026, India. potential (TBI) for the calculation of perfect [9] and defect properties of ionic solids [8,10 to 131. These three-body interactions arise from the charge transfer mechanism when the ions overlap [9] in the perfect lattice.…”

Section: Introductionmentioning

confidence: 99%

“…These three-body interactions arise from the charge transfer mechanism when the ions overlap [9] in the perfect lattice. These interactions were considered explicitly in the defect region to calculate defect formation energies in ionic solids for the first time in our earlier papers [8]. It has been shown that the calculated values of Schottky defect formation energies of a wide variety of ionic solids from the three-body force shell model (TSM) agree reasonably well with experimental results and in most cases predict better results than our own shell model calculations in which the effect of three-body forces is not considered.…”

Section: Introductionmentioning

confidence: 99%

“…In the present paper we report calculated values of formation energies and binding energies of vacancy pairs in NaCl and KC1 by incorporating the three-body interaction potential in the framework of a modified three-body force PPI model [8]. In this approach the immediate neighbours of the vacancy pair (called region I) are considered as discrete and the remaining part of the crystal (region 11) as continuum.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Charge transfer effect on formation and binding energies of vancancy pairs in NaCl and KCl

Rao

Sanyal

1991

Physica Status Solidi (b)

View full text Add to dashboard Cite

Charge transfer effect on formation and binding energies of a vacancy pair in NaCl and KCl solids is investigated by using a sophisticated model potential, which includes long range many body forces. These forces have a strong influence on the relaxing ions and mechanism of polarization. The formation energy and binding energy calculated from this potential are in good agreement with experiment.Mit einem komplizierten Modellpotential, das weitreichende Vielkorperkrafte einschlieot, wird der LadungstransfereinfluB auf die Bildungs-und Bindungsenergien eines Leerstellenpaars in NaC1-und KCI-Festkorpern untersucht. Diese Krafte haben einen starken EinfluR auf die relaxierenden Ionen und Polarisationsmechanismen. Die Bildungsfnergie-und Bindungsenergieberecl-nungen mit diesem Potential sind mit dem Experiment in guter Ubereinstimmung.

show abstract

Formation Volume of Schottky Defects (Vacancies) in Inorganic and Organic Compounds and the Defect Formation Mechanism of Melting

Bollmann¹

1992

Cryst. Res. Technol.

View full text Add to dashboard Cite

The formation volume Vs of Schottky defects is given by V, = (h$L) A V, with h, = 8L (formation enthalpy h, of Schottky defects and heat L of fusion given in same units; A V , = change of volume due to melting). If there are phase transitions within the solid, L and A 5 must be replaced by ( L + A H , ) and by (AV, + AV,), respectively ( A H , and Al/; refer to the heat(s) of transition(s) and to the volume change(s) due to transition(s), resp.). The pressure dependence of the melting point is dT,/dpIndependent on the sign of V, any increase of the Schottky defect (vacancy) concentration above the maximum concentration possible within the solid decreases the melting point thus resulting in the observed surface melting. The melting point is fixed by the characteristics of Schottky defect formation (hs, s,, 5) and by the bulk modulus of the solid (s, = formation entropy of Schottky defects).die mit dem Phasenubergang bzw. den Phaseniibergangen verbunden sind). Die Druckabhangigkeit der Schmelztemperatur ist dT,/dp = (T,,V,)/h,. Unabhangig vom Vorzeichen von V, wurde jede Erhohung der Schottky-Defekt-Konzentration uber die im Festkorper maximal mogliche Konzentration hinaus T, erniedrigen. Das fuhrt zum stets beobachteten Schmelzen an der Oberflache des Festkorpers. Der Schmelzpunkt ist durch Bildungsenthalpie, -entropie und -volumen der Schottky-Defekte sowie den Kompressionsmodul B des Kristalls festgelegt.

show abstract

Effect of three-body forces on Schottky defect energy of alkali halides

Cited by 6 publications

References 37 publications

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

Lattice Dynamics of Transition Metal Oxides-An Application to FeO in the Paramagnetic Phase

Charge transfer effect on formation and binding energies of vancancy pairs in NaCl and KCl

Formation Volume of Schottky Defects (Vacancies) in Inorganic and Organic Compounds and the Defect Formation Mechanism of Melting

Contact Info

Product

Resources

About