Analysis of thermodynamic properties for Pd-based bulk metallic glasses

Abstract

The analysis of temperature dependent thermodynamic parameters; Gibb's free energy difference (ΔG), entropy difference (ΔS) and enthalpy difference (ΔH) between the undercooled liquid and the corresponding equilibrium solid phases has been proved to be highly beneficial in the study of the thermodynamic behaviour of bulk metallic glass (BMG) forming melts. In last two decades, Pd based alloys were found to form bulk glass phases. In present study, the three thermodynamic parameters viz., ΔG, ΔS and ΔH are calculated theoretically in the entire temperature range Tm (melting temperature) to Tg (glass transition temperature) for Pd-based three samples of BMGs; Pd40Ni40P20, Pd40Cu30Ni10P20 and Pd43Cu27Ni10P20 on the basis of Taylor's series expansion. A comparative study is also made between the present result and the result obtained experimentally as well as on the basis of expressions proposed by the earlier researchers. An attempt is also been made to relate the reduced glass transition temperature with glass forming ability for all three BMGs.