skip to main content

DOE PAGESDOE PAGES

Title: Spontaneous liquid crystal and ferromagnetic ordering of colloidal magnetic nanoplates

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 magnetomechanical effects. A longstanding interest and challenge has been to make such suspensions macroscopically ferromagnetic, that is having uniform magnetic alignment in the absence of a field. Here we report a fluid suspension of magnetic nanoplates that spontaneously aligns into an equilibrium nematic liquid crystal phase that is also macroscopically ferromagnetic. We find 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.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [5] ;  [1] ;  [1] ;  [1]
  1. Univ. of Colorado, Boulder, CO (United States)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
  3. Case Western Reserve Univ., Cleveland, OH (United States)
  4. Jozef Stefan Inst. (IJS), Ljubljana (Slovenia)
  5. Jozef Stefan Inst. (IJS), Ljubljana (Slovenia); Univ. of Ljubljana, Ljubljana (Slovenia)
Publication Date:
OSTI Identifier:
1255545
Grant/Contract Number:
AC02-05CH11231; DMR-0820579; DMR-1420736
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY