Open Access Nano Express

Phononic and magnonic dispersions of surface waves on a permalloy/BARC nanostructured array

Huihui Pan1, Vanessa Li Zhang1, Kai Di1, Meng Hau Kuok1*, Hock Siah Lim1*, Ser Choon Ng1, Navab Singh2 and Adekunle Olusola Adeyeye3*

Author affiliations

1 Department of Physics, National University of Singapore, Singapore 117542, Singapore

2 Institute of Microelectronics, Agency for Science, Technology and Research, Singapore 117685, Singapore

3 Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore

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Citation and License

Nanoscale Research Letters 2013, 8:115  doi:10.1186/1556-276X-8-115

Published: 2 March 2013

Abstract

Phononic and magnonic dispersions of a linear array of periodic alternating Ni80Fe20 and bottom anti-reflective coating nanostripes on a Si substrate have been measured using Brillouin light scattering. The observed phononic gaps are considerably larger than those of laterally patterned multi-component crystals previously reported, mainly a consequence of the high elastic and density contrasts between the stripe materials. Additionally, the phonon hybridization bandgap has an unusual origin in the hybridization and avoided crossing of the zone-folded Rayleigh and pseudo-Sezawa waves. The magnonic band structure features near-dispersionless branches, with unusual vortex-like dynamic magnetization profiles, some of which lie below the highly-dispersive fundamental mode branch. Finite element calculations of the phononic and magnonic dispersions of the magphonic crystal accord well with experimental data.

Keywords:
Phononic and magnonic dispersions; Bandgaps; Brillouin light scattering; Magphonic crystal