Skip to main content
Article
Raman Characterization of Phonon Confinement and Strain Effects from Latent Ion Tracks in α-Quartz
Journal of Raman Spectroscopy
  • Maria C. Garcia Toro
  • Miguel L. Crespillo
  • Jose Olivares
  • Joseph T. Graham, Missouri University of Science and Technology
Abstract

This study reports phonon confinement and strain effects in the Raman spectrum of ion-irradiated and subsequently etched α-quartz. Y- and Z-cut α-quartz single crystals were irradiated at room temperature with 20-MeV Ni6+ and 40-MeV I7+ ions. Latent ion tracks were produced with areal densities ranging from the isolated track regime to the overlapping track regime (nominal fluences of 1 × 109, 1 × 1010, and 1 × 1011 ions cm-2). Nanowell structures were revealed after vapor etching with hydrofluoric acid (HF) aqueous solutions. A phonon confinement model was invoked to explain the observed changes in the shape of the strong Raman peak located around 463 cm-1. Phonon coherence lengths of the irradiated samples were determined by fitting the confinement model to the experimental data. It was found that the phonon coherence lengths (L) decreased with increasing fluence (L ~ 66 nm for samples irradiated with 1 × 109 ions cm-2, L ~ 58 nm at 1 × 1010 ions cm-2, and L ~ 45 nm at 1 × 1011 ions cm-2), suggesting that ion tracks may confine optical phonons in quartz. An additional contribution to the upshift was observed at the highest fluence. This was attributed to a contribution from lattice strain when track separations are small and the overlapping strain fields around ion tracks extend through a large volume fraction of the crystal. Through an empirical correlation, the induced stress was estimated to be on the order of 100 MPa.

Department(s)
Nuclear Engineering and Radiation Science
Comments
This work was supported by the Nuclear Regulatory Commission Faculty Development Grant NRC-HQ-84-15-G-0044. Also, the authors want to thank the Materials Research Center (MRC) at Missouri S&T for its support and use of equipment.
Keywords and Phrases
  • Ion tracks,
  • Phonon confinement,
  • Raman line-shape analysis,
  • Swift heavy ions,
  • α-quartz
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2021 Wiley, All rights reserved.
Publication Date
6-1-2021
Publication Date
01 Jun 2021
Disciplines
Citation Information
Maria C. Garcia Toro, Miguel L. Crespillo, Jose Olivares and Joseph T. Graham. "Raman Characterization of Phonon Confinement and Strain Effects from Latent Ion Tracks in α-Quartz" Journal of Raman Spectroscopy Vol. 52 Iss. 6 (2021) p. 1185 - 1192 ISSN: 0377-0486; 1097-4555
Available at: http://works.bepress.com/joseph-graham/57/