A new model for the lattice dynamics of Zn–Cd chalcogenides

1985 ◽  
Vol 63 (4) ◽  
pp. 494-497 ◽  
Author(s):  
R. K. Ram ◽  
S. S. Kushwaha ◽  
S. P. Singh
Keyword(s):  
Satisfactory Agreement ◽  
Wave Vector ◽  
Lattice Dynamics ◽  
Normal Modes ◽  
Ionic Model ◽  
Frequency Wave ◽  
New Model ◽  
Zinc Blende ◽  
Cd Chalcogenides ◽  
Zinc Blende Structure

A noncentral second neighbour ionic model is proposed for calculating frequency wave vector dispersion relations for the normal modes of vibrations for zinc and cadmium tellurides crystallizing in the zinc blende structure. The model takes into account the change in energy owing to rotation of bonds. The calculated phonon frequencies show a reasonably satisfactory agreement with the available optic data.

Deformation dipole model and lattice dynamics of zinc-blende-structure compounds

1975 ◽  
Vol 12 (10) ◽  
pp. 4346-4355 ◽  
Author(s):  
K. Kunc ◽  
M. Balkanski ◽  
M. A. Nusimovici
Keyword(s):  
Lattice Dynamics ◽  
Dipole Model ◽  
Zinc Blende ◽  
Zinc Blende Structure

Theory of the lattice vibrations of germanium

1959 ◽  
Vol 253 (1273) ◽  
pp. 260-276 ◽  
Keyword(s):  
Elastic Constants ◽  
Lattice Dynamics ◽  
Normal Modes ◽  
Wave Number ◽  
Simple Explanation ◽  
Lattice Vibrations ◽  
Germanium Crystal ◽  
Frequency Wave ◽  
Oppositely Charged ◽  
Good Agreement

Previous attempts to explain the frequency-wave number relations for the normal modes of germanium, which have been determined experimentally by Brockhouse & Iyengar, have required the assumption of force constants between atoms which are relatively far apart. The theory then involves a large number of undetermined parameters which have no obvious physical justification, and the fact that the elastic constants of germanium satisfy an identity which might suggest that only interactions between adjacent atoms are important, has to be dismissed as a coincidence. In this paper we extend the Born-von Kármán theory of lattice dynamics to apply to a simple model of the germanium crystal, in which each atom is regarded as a charged core coupled to an oppositely charged shell. This gives the atom the property of polarizability, not only in an electric field but also under the influence of bonding interactions between adjacent atoms. On the basis of this model, the frequency-wave number relations can be reasonably well accounted for with only two disposable parameters, and a simple explanation is provided of the fact that the elastic constants satisfy Born’s identity. The value deduced for the polarizability of a germanium atom, using the neutron spectroscopy data of Brockhouse & Iyengar, is in good agreement with that determined directly from the dielectric constant. An extension of the theory of Mashkevich & Tolpygo provides some theoretical justification for the use of a shell model for germanium.

Lattice dynamics properties of XAs (X=Al, Ga and In) with zinc-blende structure from first-principle calculations

2012 ◽  
Vol 73 (8) ◽  
pp. 1034-1039 ◽  
Author(s):  
Xingxiu Li ◽  
Xiaoma Tao ◽  
Ran Li ◽  
Hongmei Chen ◽  
Yifang Ouyang ◽  
...  
Keyword(s):  
Lattice Dynamics ◽  
First Principle ◽  
First Principle Calculations ◽  
Zinc Blende ◽  
Zinc Blende Structure

Lattice dynamics of crystals of the calcite structure. I. Normal frequencies and normal modes at zero wave vector

1970 ◽  
Vol 42 (2) ◽  
pp. 485-496 ◽  
Author(s):  
M. Plihal ◽  
G. Schaack
Keyword(s):  
Wave Vector ◽  
Lattice Dynamics ◽  
Normal Modes

scholarly journals Surface half-metallicity of CrAs in the zinc-blende structure

2002 ◽  
Vol 66 (1) ◽  
Author(s):  
I. Galanakis
Keyword(s):  
Half Metallicity ◽  
Zinc Blende ◽  
Zinc Blende Structure

Sputter Deposition of Fe-Co Nitride for Ferromagnetic Granular Nitride Thin Film

2009 ◽  
Vol 631-632 ◽  
pp. 327-331 ◽  
Author(s):  
K. Sakon ◽  
Y. Hirokawa ◽  
Yasuji Masubuchi ◽  
Shinichi Kikkawa
Keyword(s):  
Thin Film ◽  
Solid Solution ◽  
Thermal Decomposition ◽  
Sputter Deposition ◽  
Composite Target ◽  
Zinc Blende ◽  
Alloy Particles ◽  
Sputter Deposited ◽  
Magneto Resistance ◽  
Zinc Blende Structure

Sputter deposited Fe0.7Co0.3 nitride thin film had zinc blende structure. It was thermally decomposed completely back to the ferromagnetic Fe0.7Co0.3 alloy above 400°C. As-deposited nitride thin films obtained in cosputtering of (Fe0.7Co0.3)1-xAlx composite target with nitrogen sputter gas were solid solutions with zinc blende (x≤0.44) and wurtzite (x>0.5) type structure, respectively. The largest magneto resistance ratio of 0.24% was observed on the Fe0.7Co0.3 alloy particles dispersed in AlN thin film obtained by thermal decomposition of the nitride solid solution with x=0.66 at 500°C.

Dynamic Stability of Ni FCC Crystal under Isotropic Tension

2013 ◽  
Vol 592-593 ◽  
pp. 47-50
Author(s):  
Petr Řehák ◽  
Miroslav Černý
Keyword(s):  
Dynamic Stability ◽  
Wave Vector ◽  
First Principles ◽  
Lattice Dynamics ◽  
Harmonic Approximation ◽  
Tensile Loading ◽  
The Other ◽  
Other Hand ◽  
Critical Strains

Lattice dynamics and stability of fcc crystal of Ni under isotropic (hydrostatic) tensile loading are studied from first principles using supercell method and a harmonic approximation. According to the results, strength of the crystal is determined by occurrence of an instability related to soft phonons with finite wave vector. On the other hand, the critical strains and stresses associated with such instabilities are only slightly lower than those related to the volumetric instability.

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