arXiv subjects

Wanisson Silva Santana

Publications and source records attributed to Wanisson Silva Santana.

4 recordsLinked to original sources

arXiv2024

Non-additive Stochastic Model for Supercooled Liquids: New Perspectives for Glass Science

We present a review of the Non-additive Stochastic Model for supercooled liquids (NSM), an efficient approach for diffusive processes that provides a suitable interpretation for the non-Arrhenius dynamics in these materials. Based on a class of non-homogeneous continuity equations, the NSM provides functions able to model the thermal behavior of the viscosity and diffusivity in fragile liquids. The model defines a rigorous physical criterion that distinguishes super-Arrhenius from sub-Arrhenius processes, establishes a robust scale of fragility, describes fragile-to-strong curves in Angell's plot, and provides an accurate fitting equation for experimental viscosity data as effective as other viscosity classic models.

cond-mat.stat-mech↗

arXiv2024

Proof-of-concept for a nonadditive stochastic model of supercooled liquids

The recently proposed non-additive stochastic model (NSM) offers a coherent physical interpretation for diffusive phenomena in glass-forming systems. This model presents non-exponential relationships between viscosity, activation energy, and temperature, characterizing the non-Arrhenius behavior observed in supercooled liquids. In this work, we fit the NSM viscosity equation to experimental temperature-dependent viscosity data corresponding to twenty-five glass-forming liquids and compare the fit parameters with those obtained using the Vogel-Fulcher-Tammann (VFT), Avramov-Milchev (AM), and Mauro-Yue-Ellison-Gupta-Allan (MYEGA) models. The results demonstrate that the NSM provides an effective fitting equation for modeling viscosity experimental data in comparison with other established models (VFT, AM and MYEGA), characterizing the activation energy in fragile liquids, presenting a reliable indicator of the degree of fragility of the glass-forming liquids.

cond-mat.stat-mech↗

arXiv2020

Non-Arrhenius behavior and fragile-to-strong transition of glass-forming liquids

Characterization of the non-Arrhenius behavior of glass-forming liquids is a broad avenue for research toward the understanding of the formation mechanisms of noncrystalline materials. In this context, this paper explores the main properties of the viscosity of glass-forming systems, considering super-Arrhenius diffusive processes. We establish the viscous activation energy as a function of the temperature, measure the degree of fragility of the system, and characterize the fragile-to-strong transition through the standard Angell's plot. Our results show that the non-Arrhenius behavior observed in fragile liquids can be understood through the non-Markovian dynamics that characterize the diffusive processes of these systems. Moreover, the fragile-to-strong transition corresponds to a change in the spatio-temporal range of correlations during the glass transition process.

cond-mat.stat-mech↗

arXiv2019

Characterization of the non-Arrhenius behavior of supercooled liquids by modeling non-additive stochastic systems

The characterization of the formation mechanisms of amorphous solids is a large avenue for research, since understanding its non-Arrhenius behavior is challenging to overcome. In this context, we present one path toward modeling the diffusive processes in supercooled liquids near glass transition through a class of non-homogeneous continuity equations, providing a consistent theoretical basis for the physical interpretation of its non-Arrhenius behavior. More precisely, we obtain the generalized drag and diffusion coefficients that allow us to model a wide range of non-Arrhenius processes. This provides a reliable measurement of the degree of fragility of the system and an estimation of the fragile-to-strong transition in glass-forming liquids, as well as a generalized Stokes-Einstein equation, leading to a better understanding of the classical and quantum effects on the dynamics of non-additive stochastic systems.

cond-mat.stat-mech↗