Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics · 1997 · 10 citations · 0 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsCrystal StructureSolid-state ChemistryCrystal SymmetryCrystallographyDiffractionElectron DiffractionOptical Properties Of SolidsPhase TransitionsCrystal Symmetry DeterminationDiffraction Pattern AnalysisDiffraction SymmetryElectron Diffraction Pattern AnalysisHeat CapacityHexagonal SymmetrySmectic PhasesSymmetry Analysis In Diffraction
Electron diffraction shows that a free-standing two-layer film of N-(4-n-butoxybenzylidene)-4-n-octylaniline exhibits smectic-A, hexatic-B, and crystal-B phases upon cooling. The hexatic-B is preceded by a phase, called hexatic-${\mathrm{B}}_{1}$, with hexatic-like positional correlations but no sixfold symmetric arcs in its diffraction pattern. The smectic-A--hexatic ${\mathrm{B}}_{1}$ transition is accompanied by a strong heat-capacity and optical-reflectivity anomaly.