miscibility gap

Area within the coexistence curve of an isobaric phase diagram (temperature vs composition) or an isothermal phase diagram (pressure vs composition).
A @MT07230@ gap is observed at temperatures below an @UT07280@ (UCST) or above the lower @C01401@ (LCST). Its location depends on pressure. In the @MT07230@ gap, there are at least two phases coexisting.
PAC, 2004, 76, 1985. 'Definition of terms related to polymer blends, composites, and multiphase polymeric materials (IUPAC Recommendations 2004)' on page 1996 (https://doi.org/10.1351/pac200476111985)