Rotating hematite cube chains
M Brics1, V Šints1, G Kitenbergs1
1MMML laboratory, Department of Physics, University of Latvia, Rīga LV-1004, Latvia.
Physical Review. E
|September 19, 2023
Summary
Researchers studied hematite cube chains in rotating magnetic fields. They discovered unique three-dimensional motion, enabling chains to catch up with the field by rolling on edges.
Area of Science:
- Physics of soft matter
- Colloidal science
- Fluid dynamics
Background:
- Two-dimensional chiral fluids were recently demonstrated using cubic hematite particles.
- Understanding the behavior of fundamental units (chains) is crucial for characterizing these fluids.
Purpose of the Study:
- Analyze the behavior of short hematite chains in static and rotating magnetic fields.
- Identify and characterize different motion regimes of these chains.
- Investigate the dynamics of out-of-plane motion.
Main Methods:
- Simulated equilibrium structures of hematite chains in static magnetic fields.
- Observed chain dynamics in rotating magnetic fields.
- Experimentally verified planar and out-of-plane motion regimes.
Main Results:
- Identified three planar motion regimes for hematite cube chains.
- Discovered an out-of-plane motion regime where chains rotate slower than the magnetic field.
- Observed chains catching up by rolling on edges and rotating in the third dimension.
- Verified similar dynamics for single cubes with gravitational effects.
Conclusions:
- Hematite cube chains exhibit complex dynamics in rotating magnetic fields.
- Out-of-plane motion is a key mechanism for chains to synchronize with external fields.
- These findings provide insights into the building blocks of 2D chiral fluids.
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