title: Two scenarios for colloidal phase transitions.
abstract: A two-dimensional assembly of charged colloidal particles induced by an alternating electric field was studied in real space by means of digital video microscopy. Phase transitions occur from a highly ordered colloidal monolayer to an isotropic suspension by changing the field strength or frequency (in the appropriate range). In particular, it is found that the strength-dependent phase transition is an infinite-order phase transition, in contrast with the frequency-dependent phase transition, which is a second-order phase transition.
authors.affiliation: Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore.
authors.forename: Ke-Qin
authors.initials: KQ
authors.lastname: Zhang
authors.forename: Xiang Y
authors.initials: XY
authors.lastname: Liu