On the scaling factor in Debye-Grueneisen model: A case study of the Mg-Zn binary system

The utility of the Debye-Grueneisen has been investigated with respect to a finite-temperature fitting parameter known as the scaling factor. This scaling factor is studied using bcc, fcc, hcp systems and the Mg-Zn binary system. Predicted Debye temperatures, using a calculated scaling factor, show good agreement with experiments and improvements over the scaling factor derived by Moruzzi et al. Finite-temperature thermodynamic properties of Mg, Zn, Mg4Zn7, MgZn2, and Mg2Zn11 are investigated to show the efficiency and improved accuracy of the calculated scaling factor. For the intermetallic compounds except Mg2Zn11, Theta D predictions are improved upon greatly by implementing a calculated scaling factor. Along the same line, heat capacity is also predicted, showing good agreement with experimental values for these compounds. For Mg2Zn11, the Debye-Grueneisen model cannot account for anomalous lattice dynamics at low temperatures.