Sustained multiferroicity in liquid crystal induced by core/shell quantum dots

Abstract

Sustained multiferroicity along with the ferromagnetic ordering in a ferroelectric liquid crystal (FLC) on incorporation of Co-ZnO/ZnO core/shell (CZZ) quantum dots (QDs) is confirmed by ferroelectric (P-E) and ferromagnetic (M-H) hysteresis measurements. An appropriate amount of CZZ QDs was added into pure FLC (KCFLC 7S) material to study its ferroelectric and ferromagnetic properties. Increased cobalt concentration in the core of CZZ QDs enhances the magnitude of saturation magnetization. The inherent magnetic field of core/shell QDs is coupled with the director field of the FLC molecules without altering the intrinsic properties of host FLC and dopant QDs, which reveals sustained multiferroic behavior. Notably, the optimized concentration of QDs does not disturb the intrinsic ferroelectric nature of the host as confirmed by ferroelectric and helical pitch measurements. The outcome of this work would be beneficial for future QD based liquid crystal displays that exhibit both electric and magnetic memory within itself.