FIZIKA A 16 (2007) 4 , 187-206

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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

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