Phase separation and Si nanocrystal formation in bulk SiO studied by x-ray scattering

Abstract

We present an x-ray scattering study of the temperature-induced phase separation and Si nanocrystal formation in bulk amorphous SiOx with x≈1. X-ray Raman scattering at the Si LII,III-edge reveals a significant contribution of suboxides present in native amorphous SiO. The suboxide contribution decreases with increasing annealing temperature between 800–1200 °C pointing toward a phase separation of SiO into Si and SiO2 domains. In combination with x-ray diffraction and small angle x-ray scattering the SiO microstructure is found to be dominated by internal suboxide interfaces in the native state. For higher annealing temperatures above 900 °C growth of Si nanocrystals with rough surfaces embedded in a silicon oxide matrix can be observed.

Atomic-scale disproportionation in amorphous silicon monoxide

“…Apparently, amorphous SiO is not a simple composite of amorphous Si and SiO 2 clusters but may have a unique atomic structure, possibly, in the interfacial regions between Si and SiO 2 domains as suggested by Hohl and co-authors 12 . Nevertheless, in spite of extensive investigations by XRD, X-ray photoelectron spectroscopy, X-ray Raman scattering, small-angle X-ray scattering and so on 12 20 21 22 , these techniques only provide average or spectroscopic information on the structure of the amorphous SiO. The unique and well-defined local atomic configurations of SiO have not been directly realized by experiments mainly because of the limitation in spatial resolution of conventional diffraction methods.…”

Pressure driven spin transition in siderite and magnesiosiderite single crystals

“…The advantage of XRS 44 , a non-resonant inelastic x-ray scattering technique, is that it allows probing low energy absorption edges by hard x-rays 45 – 48 . The method is sensitive to local coordination 49 and oxidation state 50 . Lately, Nyrow et al .…”

Planning, performing and analyzing X-ray Raman scattering experiments

“…The advent of third-generation synchrotron radiation facilities and especially the recent development of new XRS instruments at various light sources (Cai et al, 2004;Fister et al, 2006;Verbeni et al, 2009;Sokaras et al, 2012) has made this technique available to a broad range of users who apply XRS in a wide range of fields, from fundamental physics (Abbamonte et al, 2004;Sternemann et al, 2005;Weissker et al, 2006) to materials sciences (Feroughi et al, 2010) and geosciences (Lee et al, 2005(Lee et al, , 2008Sternemann et al, 2013). What makes XRS unique and so valuable is the ability to obtain soft X-ray absorption spectra (XAS), i.e.…”