Tricritical- and critical-point melting transitions of commensurate CO on graphite

Abstract

Heat-capacity studies of the melting transition of the commensurate (\ensuremath{\surd}3 \ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}3 ) phase of CO on graphite yield, at appropriate coverages, critical exponents consistent with that expected for two-dimensional three-state-Potts tricritical and two-dimensional three-state-Potts critical-phase transitions.