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Chiral Nanomagnets

2014

Article

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We report on the enhanced optical properties of chiral magnetic nanohelices with critical dimensions comparable to the ferromagnetic domain size. They are shown to be ferromagnetic at room temperature, have defined chirality, and exhibit large optical activity in the visible as verified by electron microscopy, superconducting quantum interference device (SQUID) magnetometry, natural circular dichroism (NCD), and magnetic circular dichroism (MCD) measurements. The structures exhibit magneto-chiral dichroism (MChD), which directly demonstrates coupling between their structural chirality and magnetism. A chiral nickel (Ni) film consisting of an array of nanohelices similar to 100 nm in length exhibits an MChD anisotropy factor g(MChD) approximate to 10(-4) T-1 at room temperature in a saturation field of similar to 0.2 T, permitting polarization-independent control of the film's absorption properties through magnetic field modulation. This is also the first report of MChD in a material with structural chirality on the order of the wavelength of light, and therefore the Ni nanohelix array is a metamaterial with magnetochiral properties that can be tailored through a dynamic deposition process.

Author(s): Eslami, Sahand and Gibbs, John G. and Rechkemmer, Yvonne and van Slageren, Joris and Alarcon-Correa, Mariana and Lee, Tung-Chun and Mark, Andrew G. and Rikken, Geert L. J. A. and Fischer, Peer
Journal: ACS PHOTONICS
Volume: 1
Number (issue): 11
Pages: 1231-1236
Year: 2014

Department(s): Micro, Nano, and Molecular Systems
Bibtex Type: Article (article)

DOI: 10.1021/ph500305z

BibTex

@article{ISI:000345542400020,
  title = {Chiral Nanomagnets},
  author = {Eslami, Sahand and Gibbs, John G. and Rechkemmer, Yvonne and van Slageren, Joris and Alarcon-Correa, Mariana and Lee, Tung-Chun and Mark, Andrew G. and Rikken, Geert L. J. A. and Fischer, Peer},
  journal = {ACS PHOTONICS},
  volume = {1},
  number = {11},
  pages = {1231-1236},
  year = {2014},
  doi = {10.1021/ph500305z}
}