Crossover between two- and three-dimensional melting in a smectic-B-smectic-A phase transition in BBOA
Stishov S. M. , Nefedov S. N. , Zisman A. N.
It is established that the curve of the first-order of phase transition smectic-i? (SB )-smectic-Λ (SA) in 7V-(4-«-butyloxybenzylidene)-4-«-octylaniline (BBOA or 40.8) terminates at the end critical point (ECP), coalescing with the curve of the second-order phase transition smectic-^-nematic (N). An increase in the volume Δ Vand entropy AS jumps on the SB-SA transition line with an increase in pressure is attributed to the crossover between twoand three-dimensional melting.