Amorphization of Ge and Si nanocrystals embedded in amorphous SiO{sub 2} by ion irradiation

Journal Article · Thu Oct 01 00:00:00 EDT 2009 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.80.144109· OSTI ID:21287081

Backman, M; Pakarinen, O H; Nordlund, K ^[1]; Djurabekova, F ^[1]; Araujo, L L; Ridgway, M C ^[2]

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1. Helsinki Institute of Physics and Department of Physics, University of Helsinki, P.O. Box 43, Helsinki FI-00014 (Finland)
2. Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

Finite-size effects become significant in nanoscale materials. When a nanocrystal is surrounded by a host matrix of a different nature, the perfection of the crystal structure is distorted by the interface formed between the nanocrystal and the matrix. The larger the surface-to-volume ratio of the nanocrystal, the higher the influence of the interface defect states on its properties. The presence of defect states in the interface can also explain the different responses of the nanocrystals (NCs) on external influences. By the combination of molecular-dynamics simulations and x-ray absorption spectroscopy measurements, we show that the amorphization of Si and Ge nanocrystals is reached at doses roughly one order of magnitude lower than those for the bulk crystals. Examining nanocrystals in the size range from 2.4 to 9 nm, we also show that the susceptibility to the amorphization decreases with increasing nanocrystal size. The finite-size effect remains significant also for the largest nanocrystals of 9 nm.

• OSTI ID: 21287081
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 80, Issue 14; Other Information: DOI: 10.1103/PhysRevB.80.144109; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION SPECTROSCOPY
AMORPHOUS STATE
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DOSES
GERMANIUM
INTERFACES
ION BEAMS
IRRADIATION
MOLECULAR DYNAMICS METHOD
NANOSTRUCTURES
SEMICONDUCTOR MATERIALS
SILICA
SILICON
SILICON OXIDES
SIMULATION
SURFACES
X-RAY SPECTRA
X-RAY SPECTROSCOPY