Anisotropic expansion and amorphization of Ga2O3 irradiated with 946 MeV Au ions

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

卷:374

Article

Tracy, Cameron L.^1,2  Lang, Maik³  Severin, Daniel⁴  Bender, Markus⁴  Trautmann, Christina^4,5  Ewing, Rodney C.² 

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

[2] Stanford Univ, Dept Geol Sci, Stanford, CA 94305 USA

[3] Univ Tennessee, Dept Nucl Engn, Knoxville, TN 37996 USA

[4] GSI Helmholtzzentrum Schwerionenforsch, D-64291 Darmstadt, Germany

[5] Tech Univ Darmstadt, Petersenstr 30, D-64287 Darmstadt, Germany

关键词: Swift heavy ions;    Ion irradiation;    X-ray diffraction;    Amorphization;    Unit cell parameters;   

DOI  :  10.1016/j.nimb.2015.08.059

来源: Elsevier

【 摘 要 】

The structural response of beta-Ga2O3 to irradiation-induced electronic excitation was investigated. A polycrystalline pellet of this material was irradiated with 946 MeV Au ions and the resulting structural modifications were characterized using in situ X-ray diffraction analysis at various ion fluences, up to 1 x 10(13) cm(-2). Amorphization was induced, with the accumulation of the amorphous phase following a single-impact mechanism in which each ion produces an amorphous ion track along its path. Concurrent with this phase transformation, an increase in the unit cell volume of the material was observed and quantified using Rietveld refinement. This unit cell expansion increased as a function of ion fluence before saturating at 1.8%. This effect is attributed to the generation of defects in an ion track shell region surrounding the amorphous track cores. The unit cell parameter increase was highly anisotropic, with no observed expansion in the [010] direction. This may be due to the structure of beta-Ga2O3, which exhibits empty channels of connected interstitial sites oriented in this direction. (C) 2015 Elsevier B.V. All rights reserved.

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