Thermodynamic potentials of metallic alloys in the undercooled liquid and solid glassy states

Fuente: arXiv
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Autores principales: Makarov, A. S., Konchakov, R. A., Kobelev, N. P., Khonik, V. A.
Formato: Preprint
Publicado: 2025
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author Makarov, A. S.
Konchakov, R. A.
Kobelev, N. P.
Khonik, V. A.
author_facet Makarov, A. S.
Konchakov, R. A.
Kobelev, N. P.
Khonik, V. A.
contents We first present a comparative analysis of temperature evolution of the excess thermodynamic potentials (state functions), the enthalpy $ΔH$, entropy $ΔS$ and Gibbs free energy $ΔΦ$, determined for \textit{i}) undercooled melts using literature data and \textit{ii}) solid glassy state calculated on the basis of calorimetry measurements using an approach proposed recently. Three metallic alloys were taken as an example for data analysis. It is found that temperature dependences $ΔH(T)$, $ΔS(T)$ and $ΔG(T)$ calculated with both approaches coincide in the supercooled liquid range (i.e. at temperatures $T_g<T<T_x$, where $T_g$ and $T_x$ are the glass transition and crystallization onset temperatures, respectively). However, the necessary conditions for this coincidence is the introduction of important changes to the above approach \textit{i}), which are related to the calculation of the melting entropy. We also introduce and calculate a dimensionless order parameter $ξ$, which changes in the range $0<ξ<1$ and characterizes the evolution of the structural order from liquid-like to crystal-like one. It is shown that the order parameter $ξ_{scl}$ calculated for the end of the supercooled liquid range (i.e. for a temperature just below $T_x$) correlates with the melt critical cooling rate $R_c$: the smaller the order parameter $ξ_{scl}$ (i.e. the closer the structure to that of the equilibrium liquid), the smaller $R_c$ is.
format Preprint
id arxiv_https___arxiv_org_abs_2507_02609
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Thermodynamic potentials of metallic alloys in the undercooled liquid and solid glassy states
Makarov, A. S.
Konchakov, R. A.
Kobelev, N. P.
Khonik, V. A.
Disordered Systems and Neural Networks
We first present a comparative analysis of temperature evolution of the excess thermodynamic potentials (state functions), the enthalpy $ΔH$, entropy $ΔS$ and Gibbs free energy $ΔΦ$, determined for \textit{i}) undercooled melts using literature data and \textit{ii}) solid glassy state calculated on the basis of calorimetry measurements using an approach proposed recently. Three metallic alloys were taken as an example for data analysis. It is found that temperature dependences $ΔH(T)$, $ΔS(T)$ and $ΔG(T)$ calculated with both approaches coincide in the supercooled liquid range (i.e. at temperatures $T_g<T<T_x$, where $T_g$ and $T_x$ are the glass transition and crystallization onset temperatures, respectively). However, the necessary conditions for this coincidence is the introduction of important changes to the above approach \textit{i}), which are related to the calculation of the melting entropy. We also introduce and calculate a dimensionless order parameter $ξ$, which changes in the range $0<ξ<1$ and characterizes the evolution of the structural order from liquid-like to crystal-like one. It is shown that the order parameter $ξ_{scl}$ calculated for the end of the supercooled liquid range (i.e. for a temperature just below $T_x$) correlates with the melt critical cooling rate $R_c$: the smaller the order parameter $ξ_{scl}$ (i.e. the closer the structure to that of the equilibrium liquid), the smaller $R_c$ is.
title Thermodynamic potentials of metallic alloys in the undercooled liquid and solid glassy states
topic Disordered Systems and Neural Networks
url https://arxiv.org/abs/2507.02609