April 30, 2024
Jafar Poursamad Bonab

Jafar Poursamad Bonab

Academic rank: Associate professor
Address: Bonab, University of Bonab
Education: Ph.D in Laser Physics
Phone: 04137745000-1643
Faculty: Faculty of Science
Department: Optics & Laser Engineering

Research

Title
Behaviour of nematic liquid crystals doped with ferroelectric nanoparticles in the presence of an electric field
Type Article
Keywords
Liquid crystal; ferrolectric nanoparticle; Freedericksz transition; electric field of FNPs; segregation effect
Researchers Mohammad Emdadi، Jafar Poursamad Bonab، Mostafa Sahrai، Farid Moghaddas

Abstract

A planar nematic liquid crystal cell (NLC) doped with spherical ferroelectric nanoparticles is considered. Polarisation of the nanoparticles are assumed to be along the NLC molecules parallel and antiparallel to the director with equal probability. The NLC molecules anchoring to the cell walls are considered to be strong, while soft anchoring at the nanoparticles surface is supposed. Behaviour of the NLC molecules and nanoparticles in the presence of a perpendicular electric field to the NLC cell is theoretically investigated. The electric field of the nanoparticles is taken into account in the calculations. Freedericksz transition (FT) threshold field in the presence of nanoparticles is found. Then, the director and particles reorientations for the electric fields larger than the threshold field are studied. Measuring the onset of the nanoparticles reorientation is proposed as a new method for the FT threshold measurement.