TY - JOUR

T1 - Electric eld driven transformations of orientational structure in chiral nematic systems with large flexoelectricity

AU - Oskirko, A.D.

AU - Ul'yanov, S.V.

AU - Valkov, A.Yu.

PY - 2020

Y1 - 2020

N2 - Transformation of the orientational structure in a plane-parallel cell of a cholesteric liquid crystal, was studied depending on the magnitude of the voltage applied to the boundary planes of the cell. The equilibrium configuration of the liquid crystal director field was found minimizing the free energy both analitically and numerically. We took into account the orientational elastic energy in the volume and at the cell boundaries, the energy of an inhomogeneous electric field, and the flexoelectric effect. Systems with large flexoelectric coefficient were studied in detail. It was found, that when small voltages are applied to the cell boundaries, a continuous Fredericks transition occurs first, and then, when certain characteristic voltage is achieved, a significant jump-like change in the orientational structure takes place, and this structure gradually changes with the further voltage increase. It is shown that various scenarios of transformation of the orientational structure can be implemented depending on the actual values of the set of material parameters of the system studied. The discovered ability to control the structure of a liquid crystal in a cell can find use in various technical devices.

AB - Transformation of the orientational structure in a plane-parallel cell of a cholesteric liquid crystal, was studied depending on the magnitude of the voltage applied to the boundary planes of the cell. The equilibrium configuration of the liquid crystal director field was found minimizing the free energy both analitically and numerically. We took into account the orientational elastic energy in the volume and at the cell boundaries, the energy of an inhomogeneous electric field, and the flexoelectric effect. Systems with large flexoelectric coefficient were studied in detail. It was found, that when small voltages are applied to the cell boundaries, a continuous Fredericks transition occurs first, and then, when certain characteristic voltage is achieved, a significant jump-like change in the orientational structure takes place, and this structure gradually changes with the further voltage increase. It is shown that various scenarios of transformation of the orientational structure can be implemented depending on the actual values of the set of material parameters of the system studied. The discovered ability to control the structure of a liquid crystal in a cell can find use in various technical devices.

UR - https://iopscience.iop.org/article/10.1088/1742-6596/1425/1/012176

M3 - Conference article

VL - 1425

JO - Journal of Physics: Conference Series

JF - Journal of Physics: Conference Series

SN - 1742-6588

M1 - 012176

ER -