ERBIUM-BASED LIQUID CRYSTAL COMPLEX FRANK CONSTANTS CALCULATION METHOD

Abstract

Bstract. Aim is to determine the Frank elastic constants of an erbium-based liquid crystal complex. Methodology. The orienting effect of a magnetic field on an erbium-based liquid crystal complex was studied by a capacitive method. The dependence of the effective values of the components of the dielectric permittivity of the complex on the magnetic field is obtained. A theoretical approach and a numerical method for determining the Frank elastic constants are proposed based on the experimental dependence of the effective values of the permittivity of a cell on a magnetic field. Results. The dependences of the permittivity of the sample on the applied magnetic field explained, and Frank elastic constants for this substance are found. Research implications. Paramagnetic nematic liquid crystal complexes based on lanthanide ions (lanthanide mesogens) possess highly efficient luminescence and anisotropy of magnetic susceptibility is anomalously large for liquid crystals. The indicated properties of nematic lanthanide mesogens make it possible to create optical media with linearly polarized luminescence for use in optoelectronic devices controlled by electric and magnetic fields.

Keywords

• liquid crystals
• lanthanide mesogens
• dielectric permittivity
• Frank elastic constants
• phase transition
• Frédericksz transition