Aluminium diboride-type structure in Ethiopian opal-CT revealed by fast Fourier transform

Research areas:

• Planète Terre

Year:

2018

Keywords:

fast Fourier transform, opal-CT, binary systems, bidisperse arrangement, Ethiopian opal, vicinal planes, scanning electron microscopy, SEM

Authors:

• J. -P. Gauthier
• N. Stephant
• Benjamin Rondeau
• J. A. Cody
• E. Fritsch

Journal:

Journal of Applied Crystallography

Volume:

51

Number:

1

Pages:

27-34

Month:

February

BibTex:

@article{Gauthier:gj5192, author = "J.-P. Gauthier and N. Stephant and Benjamin Rondeau and J. A. Cody and E. Fritsch", abstract = "Invisible on a scanning electron microscope image of the surface of an Ethiopian opal rough fracture, a periodic arrangement was detected by fast Fourier transform. Using a mask to eliminate the continuous background and keeping only the bright spots in the reciprocal space (fast Fourier transform pattern), an image reconstructed by inverse fast Fourier transform (IFFT) emphasizes a very regular bidisperse array. Taken on a vicinal plane, the image of the successive steps of the stacking allows identification of the crystallographic structure and estimation of the parameters of this aluminium diboride-type photonic crystal. In addition, another more complex IFFT image allowed confirmation of the structure and determination of the crystallographic indexing of the steps, despite image deformation due to the tilt of the vicinal plane under the electron beam.", doi = "10.1107/S1600576717016387", extra = "PICL", journal = "Journal of Applied Crystallography", keywords = "fast Fourier transform, opal-CT, binary systems, bidisperse arrangement, Ethiopian opal, vicinal planes, scanning electron microscopy, SEM", month = "Feb", number = "1", pages = "27--34", title = "{A}luminium diboride-type structure in {E}thiopian opal-{CT} revealed by fast {F}ourier transform", url = "https://doi.org/10.1107/S1600576717016387", volume = "51", year = "2018", }

Abstract:

Invisible on a scanning electron microscope image of the surface of an Ethiopian opal rough fracture, a periodic arrangement was detected by fast Fourier transform. Using a mask to eliminate the continuous background and keeping only the bright spots in the reciprocal space (fast Fourier transform pattern), an image reconstructed by inverse fast Fourier transform (IFFT) emphasizes a very regular bidisperse array. Taken on a vicinal plane, the image of the successive steps of the stacking allows identification of the crystallographic structure and estimation of the parameters of this aluminium diboride-type photonic crystal. In addition, another more complex IFFT image allowed confirmation of the structure and determination of the crystallographic indexing of the steps, despite image deformation due to the tilt of the vicinal plane under the electron beam.