Spontaneous Liquid Crystal and Ferromagnetic Ordering of Colloidal Magnetic Nanoplates
Abstract
Ferrofluids are familiar as colloidal suspensions of ferromagnetic nanoparticles in aqueous or organic solvents. The dispersed particles are randomly oriented but their moments become aligned if a magnetic field is applied, producing a variety of exotic and useful magneto-mechanical effects. A longstanding interest and challenge has been to make such suspensions macroscopically ferromagnetic, that is having uniform magnetic alignment in absence of a field. Here we report a fluid suspension of magnetic nanoplates which spontaneously aligns into an equilibrium nematic liquid crystal phase that is also macroscopically ferromagnetic. Its zero-field magnetization produces distinctive magnetic self-interaction effects, including liquid crystal textures of fluid block domains arranged in closed flux loops, and makes this phase highly sensitive, with it dramatically changing shape even in the Earth's magnetic field.
Keywords
Cite
@article{arxiv.1510.02161,
title = {Spontaneous Liquid Crystal and Ferromagnetic Ordering of Colloidal Magnetic Nanoplates},
author = {Min Shuai and Arthur Klittnick and Yongqiang Shen and Gregory P. Smith and Michael R. Tuchband and Chenhui Zhu and Rolfe G. Petschek and Alenka Mertelj and Darja Lisjak and Martin Čopič and Joseph E. Maclennan and Matthew A. Glaser and Noel A. Clark},
journal= {arXiv preprint arXiv:1510.02161},
year = {2016}
}