Physical Society Colloquium
Interview for Faculty Position
From hard balls to soft balls to dipolar
balls:
Tailoring crystal structure, and following the dynamics of
crystallization in colloids
Anand Yethiraj
UBC
Colloidal suspensions can be useful model systems for phase transitions and
crystal nucleation. Side-stepping the complex interactions in atomic solids,
much can be learned about crystallization by treating the atoms as hard
balls. Colloidal suspensions (identical microspheres in a liquid medium)
provide an experimental model system where the interparticle interactions can
be made hard-sphere like. I present experiments that simultaneously extend
the hard-ball colloidal model system by adding repulsive and dipolar
interactions, the latter with an external a.c. electric field which acts as a
surrogate thermodynamic pressure variable.
This increase in complexity results in a rich phase behaviour that is tunable
with the electric field, and makes possible a controlled and reversible
kinetics study across a colloidal-crystalline phase boundary. Exciting
directions for future work will be discussed.
Wednesday, March 12th 2003, 16:00
Ernest Rutherford Physics Building, R.E. Bell Conference Room (room 103)
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