Phonon dynamics of glassy copper alloys

Abstract

The well recognized model potential is used to investigate the phonon properties for five glassy Copper alloys viz. Cu 57 Zr 43 , Cu 60 W 40 , Cu 33 Y 67 , Cu 43 Ti 57 and Cu 66 Ti 34 . The thermodynamic and elastic properties are also computed from the elastic limits of the phonon dispersion curves (PDC). Three theoretical approaches given by Hubbard-Beeby (HB), Takeno-Goda (TG) and Bhatia-Singh (BS) are used in the present study to compute the PDC. Five local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are employed to see the effect of exchange and correlation in the aforesaid properties.

Vibrational dynamics of Ni-glassy alloys

“…In the present study, for TM-LA, TM-TM and TM-M metallic glasses, the pair potential is computed using [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]29],…”

“…This form has the feature of a Coulombic term outside the core and varying cancellation due to repulsive and attractive contributions to the potential within the core in real space. The detailed information of this potential is given in the literature [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The model potential parameter r C is calculated from the well known formula [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] as follows:…”

“…The phonon dynamics of Ni 31 Dy 69 , Ni 36 Zr 64 , Ni 60 Nb 40 and Ni 81 B 19 metallic glasses is not reported previously using model potential formalism. Recently, we have reported the vibrational properties of some binary metallic glasses [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”

“…Ni 31 Dy 69, Ni 33 Y 67 , Ni 36 Zr 64 , Ni 50 Zr 50 , Ni 60 Nb 40 and Ni 81 B 19 using well recognized model potential [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The thermodynamics and elastic properties such as longitudinal sound velocity υ L , transverse sound velocity υ T , isothermal bulk modulus B T , modulus of rigidity G, Poisson's ratio , Young's modulus Y and Debye temperature D are computed from the elastic limit of the dispersion relation.…”

“…The phenomenological theory of Hubbard-Beeby [3] in the random phase approximation is employed to generate the phonon dispersion curves (PDC). The most important ingredient of the PDC is pair potential computed theoretically in Wills-Harrison (WH) [29] form from the well recognized model potential [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”