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FIZIKA A 19 (2010) 4 , 241-256
 
STRUCTURAL, ELASTIC, ELECTRONIC AND LATTICE DYNAMIC PROPERTIES OF
GaPxAsySb1−x−y ALLOYS LATTICE MATCHED TO DIFFERENT SUBSTRATES
B. GHEBOULIa, M. A. GHEBOULIb and M. FATMIc
aLaboratory for Studying Surfaces and Interfaces of Solid Maretials, University Ferhat Abbas, Sétif 19000, Algeria
E-mail address: bghebouli@yahoo.fr
bDepartement of Physics, University Center, Bordj-Bou-Arréridj 34000, Algeria
cResearch Unit on Emerging Materials, University Ferhat Abbas, Sétif 19000, Algeria
Received 17 July 2010; Accepted 9 February 2011
Online 2 May 2011
Information on the energy band gaps, the lattice parameter and
the lattice matching to available substrates is a prerequisite
for many practical applications. A pseudopotential plane-wave
method, as implemented in the ABINIT code, is used to the
GaPxAsySb1−x−y quaternary alloy lattice matched
to GaAs and InP substrates to predict their energy band gaps,
elastic constants and lattice dynamic properties. The ranges
of compositions for which the alloy is lattice-matched to
GaAs and InP are determined. A very good agreement is obtained
between the calculated values and the available experimental
data of GaAs and GaAs0.5Sb0.5 parents. The compositional
dependence of direct and indirect band gaps has been
investigated. Note that a phase transition occurred at
As composition of 0.018 and 0.576 for GaPxAsySb1−x−y
within InP and GaAs substrates. The static and high-frequency
dielectric constants and refractive index are indeed
inversely proportional (proportional) to the fundamental band
gap for GaPxAsySb1−x−y within InP (GaAs) substrates.
We study the variation of elastic constants, the optical
phonon frequencies (ωTO and ωLO)
and the Born effective charge Z* with As concentration.
PACS numbers: 61.72.Vv, 61.43.Bn
UDC 538.911, 538.951
Keywords: structural properties, electronic properties, first principles
calculations, lattice dynamic properties, Born effective charge, elastic properties
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