|
FIZIKA A 16 (2007) 4 , 187-206
 
COMPUTATION OF PHONON DISPERSION IN NON-CRYSTALLINE Mg-BASED ALLOYS
ADITYA M. VORA
Parmeshwari 165, Vijaynagar Area, Hospital Road, Bhuj - Kutch, 370 001, Gujarat, India
E-mail address: voraam@yahoo.com
Received 6 March 2006; Revised manuscript received 19 February 2007
Accepted 15 December 2007 Online 8 February 2008
The computation of the phonon dispersion curves (PDC) and the related properties
of three Mg-based metallic glasses, viz. Mg70Zn30, Mg84Ni16
and Mg85.5Cu14.5, are made using the well recognized model
potential of Gajjar et al. The pseudo-alloy atom model is applied for the first
time instead of the Vegard's law. The three theoretical approaches given by
Hubbard-Beeby, Takeno-Goda and Bhatia-Singh are used in the present study to
compute the PDC of the systems. Five local-field correction functions proposed
by Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. are employed
for the first time to see the effects of exchange and correlation. The
thermodynamic and elastic properties are computed from the elastic limits of the
PDC and found to be in qualitative agreement with the available theoretical or
experimental data. The present findings for the PDC of Mg70Zn30
alloy are found in fair agreement with available theoretical and experimental
data.
PACS numbers: 63.50.+x, 65.60.+a
UDC 538.911, 539.31
Keywords: pair potential, metallic glasses, elasticity, phonons, thermodynamic
properties, computer simulations
|
