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Updated: May 31, 2026
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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Heterogeneous dynamics and ageing in a dense ferro-glass
E Wandersman1, E Dubois, V Dupuis
1Université Pierre et Marie Curie-Paris 6, Laboratoire Liquides Ioniques et Interfaces Chargées (UMR 7612 UPMC/CNRS/ESPCI), 4, place Jussieu,-case 51, 75252 Paris Cedex 05, France.
Summary
Repulsive magnetic fluids exhibit dynamical freezing. Their out-of-equilibrium dynamics, studied via x-ray photon correlation spectroscopy, show age-dependent relaxation following a compressed exponential law.
Area of Science:
- Soft Matter Physics
- Materials Science
- Rheology
Background:
- Repulsive magnetic fluids display dynamical freezing at a critical volume fraction (Φ(*)).
- This freezing phenomenon is influenced by the system's physico-chemistry.
- Understanding the out-of-equilibrium dynamics is crucial for characterizing fluid behavior.
Purpose of the Study:
- To determine the critical volume fraction (Φ(*)) using a magneto-optical technique.
- To investigate the out-of-equilibrium dynamics of a glass-forming magnetic fluid (at Φ = 1.2Φ(*)).
- To analyze the relaxation behavior and deduce dynamical susceptibility (χ).
Main Methods:
- Magneto-optical technique for determining Φ(*).
- X-ray photon correlation spectroscopy (XPCS) for studying dynamics.
- Analysis of intensity auto-correlation functions.
- Time-resolved correlation analysis.
Main Results:
- The critical volume fraction Φ(*) was determined.
- Out-of-equilibrium dynamics were found to be age-dependent.
- Relaxation followed a compressed exponential law.
- Characteristic relaxation time scaled inversely with the scattering vector (Q).
Conclusions:
- The study provides insights into the dynamical freezing and out-of-equilibrium behavior of repulsive magnetic fluids.
- Age-dependent relaxation and compressed exponential behavior characterize the fluid's dynamics.
- Dynamical susceptibility (χ) was successfully deduced, offering further understanding of the system's response.
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