Magnesium behavior and structural defects in Mg⁺ ion implanted silicon carbide

Journal Article · Sun Mar 01 00:00:00 EST 2015 · Journal of Nuclear Materials

DOI:https://doi.org/10.1016/j.jnucmat.2014.12.071· OSTI ID:1166816

Jiang, Weilin ^[1]; Jung, Hee Joon ^[1]; Kovarik, Libor ^[1]; Wang, Zhaoying ^[1]; Roosendaal, Timothy J. ^[1]; Zhu, Zihua ^[1]; Edwards, Danny J. ^[1]; Hu, Shenyang ^[1]; Henager, Charles H. ^[1]; Kurtz, Richard J. ^[1]; Wang, Yongqiang ^[2]

---

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

As a candidate material for fusion reactor applications, silicon carbide (SiC) undergoes transmutation reactions under high-energy neutron irradiation with magnesium as the major metallic transmutant; the others include aluminum, beryllium and phosphorus in addition to helium and hydrogen gaseous species. The impact of these transmutants on SiC structural stability is currently unknown. This study uses ion implantation to introduce Mg into SiC. Multiaxial ion-channeling analysis of the as-produced damage state suggests that there are preferred Si <100> interstitial splits. The microstructure of the annealed sample was examined using high-resolution scanning transmission electron microscopy. The results show a high concentration of likely non-faulted tetrahedral voids and possible stacking fault tetrahedra near the damage peak. In addition to lattice distortion, dislocations and intrinsic and extrinsic stacking faults are also observed. Magnesium in 3C-SiC prefers to substitute for Si and it forms precipitates of cubic Mg₂Si and tetragonal MgC₂. The diffusion coefficient of Mg in 3C-SiC single crystal at 1573 K has been determined to be 3.8±0.4×10e^-19 m²/sec.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1166816
• Report Number(s): PNNL-SA-105877; 44713; AT2030110
• Journal Information: Journal of Nuclear Materials, Vol. 458, Issue C; ISSN 0022-3115
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
Magnesium behavior
structural defects
ion implantation
SiC
Environmental Molecular Sciences Laboratory