Neutron irradiation induced amorphization of silicon carbide

• Published in: Journal of nuclear materials Vol. 273; no. 2; pp. 213 - 220
• Main Authors: Snead, L.L, Hay, J.C
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.1999; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Neutron radiation effects; Physical radiation effects, radiation damage; Physics; Structure of solids and liquids; crystallography; R03; S04; N01; A06; R04; Inorganic compounds; Electron diffraction; Amorphization; Physical radiation effects; Neutrons; Silicon carbides; Binary compounds; XRD; Hardness; Experimental study; TEM
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/S0022-3115(99)00023-9

This paper provides the properties of bulk stoichiometric silicon carbide which has been amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60°C to a total fast neutron fluence of 2.6 × 10 25 n/m 2. Amorphization was seen in both materials as evidenced by TEM, electron diffraction and X-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density (−10.8%), elastic modulus as measured using a nanoindentation technique (−45%), hardness as measured by nanoindentation (−45%), and standard Vickers hardness (−24%). Similar property changes are observed for the amorphized CVD SiC. Using measured thermal conductivity data for the CVD SiC sample, the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than ∼125°C.