Evidence of a magnetic-field-induced isotropic-nematic phase transition is presented for a colloidal suspension of monodisperse fd virus, a semiflexible particle with a length-to-diameter ratio of ∼140. The dynamics of the phase transition are slow enough to study the unstable portion of the phase diagram and the subsequent phase separation.

• Received 11 August 1993

DOI:https://doi.org/10.1103/PhysRevLett.71.3509