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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
Calculated properties of field-induced aggregates in ferrofluids
1Department of Physics and Astronomy, University of Maine, Orono, Maine 04469-5709, USA.
Summary
We calculated the critical radius of ferrofluid aggregates, predicting their size and spacing. Our model, including entropy, accurately forecasts labyrinth patterns, matching experimental data for ferrofluids and magnetorheological fluids.
Area of Science:
- Physics
- Materials Science
- Fluid Dynamics
Background:
- Ferrofluids exhibit complex aggregate structures under external magnetic fields.
- Understanding aggregate formation is crucial for controlling ferrofluid behavior.
Purpose of the Study:
- To calculate the critical radius of cylindrical ferrofluid aggregates.
- To model aggregate radius and spacing as functions of external field and plate separation.
- To predict the onset of labyrinth patterns in thin ferrofluid layers.
Main Methods:
- Minimizing the Helmholtz free energy to determine critical aggregate radius.
- Developing a theoretical model that incorporates entropy effects.
- Comparing model predictions with experimental data.
Main Results:
- The critical radius of cylindrical aggregates was calculated.
- The model successfully predicts aggregate radius and spacing.
- The model provides reasonable predictions for the onset of labyrinth patterns.
Conclusions:
- The developed model accurately predicts ferrofluid aggregate behavior.
- The findings are validated by experimental data from ferrofluids and magnetorheological fluids.
- This work advances the understanding of magnetic fluid dynamics and pattern formation.
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