Publication: Second and third order elastic constants of double hexagonal close packed crystal: Application to praseodymium and neodymium
Date
01-01-1979
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Abstract
The method of homogeneous deformation has been applied to obtain theoretical expressions for the second order elastic (SOE) and third order elastic (TOE) constants of an ideal dhcp lattice. Two body interactions alone have been considered between the origin atom and six other kinds of atoms. The expressions obtained for the TOE constants have been employed to calculate the TOE constants for the metals Pr and Nd whose c to a ratio is very nearly equal to the ideal value. The Anderson-Grüneisen parameter for the two metals is calculated using their respective TOE constants. Anderson's theory is used to calculate the temperature dependence of the bulk modulus Bs for these two metals and is compared with the èxperimental values. The agreement is good. The low temperature limit ḠgL of the volume Grüneisen function has been obtained using the respective theoretical TOE constants of these two metals. The variation of a a0 and v v0 with hydrostatic pressure up to 100 kbar has been calculated using the theoretical TOE constants and Thurston's extrapolation formula for both Pr and Nd. © 1979.