The results of a high-resolution x-ray-diffraction study of the smectic phases in mixtures of DB7OCN and 8OCB show that the incommensurate smectic-Ai2 phase, previously reported in this mixture, is in fact a coexistence of the partially bilayer smectic-Ad and the bilayer smectic-A2phases at a first-order phase transition between them.
Physical Review Letters
Copyright 1991 American Physical Society. Available on publisher's site at http://dx.doi.org/10.1103/PhysRevLett.67.322.
Kumar, Satyendra; Chien, Li; Surendranath, V. (1991). Absence of the Incommensurate Smectic-A Phase in DB7OCN+8OCB Mixtures. Physical Review Letters 67(3) 322-325. doi: 10.1103/PhysRevLett.67.322. Retrieved from https://oaks.kent.edu/phypubs/4