Abstract
CB15/E9 mixtures submitted to an electric field exhibit a tetragonal phase BPX, having a D10 4(I4122) symmetry and two hexagonal phases BPH3d and BPH2d The Kossel diagram technique allows us (a) to confirm the hexagonal symmetry of BPH3d and to determine precisely its space group D2 6 (P6222) and (b) to study the field-induced phase transitions between BP II, BPX and BPH3d. We show that the BP II → BPH3d transition is a continuous deformation involving a dilatation in the field direction and a shear perpendicular to this direction. The BP II → BPX and BPX → BPH3d transitions are discontinuous.