Neutron-irradiation-induced crystalline defects in beta-silicon nitride and their thermal stability

作者：Yano Toyohiko^*; Yamagami Tomoyuki; Yoshida Katsumi; Akiyoshi Masafumi

来源：Journal of Nuclear Materials, 2011, 417(1-3): 972-975.

DOI：10.1016/j.jnucmat.2010.12.190

A hot-pressed Si(3)N(4) was neutron-irradiated in the JOYO experimental fast reactor. The ranges of irradiation fluence and temperature were (0.4-3.7) x 10(26) n/m(2) (E > 0.1 MeV) and (377-727) degrees C, respectively. Based on high-resolution electron microscope observation, several kinds of tiny interstitial dislocation loops on the {1 0 (1) over bar 0} or {1 1 (2) over bar 0} planes were identified. It was clarified that area density and average size of each planar defect was greater after irradiation to higher doses at higher temperatures. The density of planar defects on {1 0 (1) over bar 0} was higher than that of on {1 1 (2) over bar 0), regardless of irradiation conditions. After annealing, size distribution of the defects on the {1 0 (1) over bar 0} planes was not changed up to 1350 degrees C in the case of the specimen irradiated at the lowest temperature (0.5 x 10(26) n/m(2) at 377 degrees C). On the other hand, the number of dislocations with diameter smaller than 4 nm decreased at over 900 degrees C and the loop size distribution shifted larger size after annealing at temperatures higher than 1350 degrees C in the case of higher irradiation temperature specimen (0.4 x 10(26) n/m(2) at 542 degrees C).

• 出版日期2011-10-1