Phase transformation and chemical decomposition of nanocrystalline SnO2 under heavy ion irradiation

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:407

Article

Cusick, Alex B.¹  Lang, Maik²  Zhang, Fuxiang³  Zhang, Jiaming⁴  Kluth, Patrick⁵  Trautmann, Christina^6,7  Ewing, Rodney C.^1,3,4 

[1] Univ Michigan, Mat Sci & Engn, Ann Arbor, MI 48109 USA

[2] Univ Tennessee, Nucl Engn, Knoxville, TN 37996 USA

[3] Univ Michigan, Earth & Environm Sci, Ann Arbor, MI 48109 USA

[4] Stanford Univ, Geol Sci, Stanford, CA 94305 USA

[5] Australian Natl Univ, Res Sch Phys & Engn, Canberra, ACT 2601, Australia

[6] GSI Helmholtz Ctr Heavy Ion Res, D-64291 Darmstadt, Germany

[7] Tech Univ Darmstadt, D-64287 Darmstadt, Germany

关键词: Swift heavy ions;    Irradiation;    Phase transformation;    Tin oxide;    Nanocrystalline;    Decomposition;    Reduction;   

DOI  :  10.1016/j.nimb.2017.05.037

来源: Elsevier

【 摘 要 】

A crystalline-to-crystalline phase transformation, including chemical decomposition, has been observed in SnO2 nanopowder irradiated by 2.2 GeV Au-197 ions. X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM) were used to characterize the transformation from tetragonal SnO2 (P4(2)/mnm) to tetragonal SnO (P4/nmm), with trace quantities of beta-Sn (14(1)/amd). At a fluence of approximately 2.0 x 10(12) ions/cm(2), diffraction maxima corresponding to SnO became clearly evident and increased in intensity as fluence increased. The proportion of SnO, as determined by Rietveld refinement of XRD data, reached 23.1 +/- 0.8% at the maximum fluence investigated of 2.4 x 10(13) ions/cm(2). Raman spectra show high photoluminescence (PL) intensity before and during initial SnO formation, indicating the importance of oxygen vacancies in the transformation process. Small-angle X-ray scattering (SAXS) analysis provided evidence of ion tracks, but no tracks were observed using high-resolution TEM (HRTEM). The transformation likely occurs through a multiple-impact mechanism, based on the accumulation of O vacancies, defect ordering, and partially localized Sn reduction. (C) 2017 Elsevier B.V. All rights reserved.

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