N. Bunjes et al. Journal of Non-Crystalline Solids 353(2007)1567-1576 B-sic b as B-sic C T=1600°c T=1700°c T=1800°c Fig. 6. Electron diffraction pattern of 5c samples thermolyzed at 1400C/2 h/Ar and subsequently annealed at: (a)1600C,( b)1700C,and (c)1800°C/5h/Ar BF Si B 100 mc Fig. 7. Bright field image and elemental distribution images of Si, C, and B of 5e thermolyzed at 1400C/5 h/Ar and subsequently annealed at 1700C/5 h/Ar. One sample of 5e was also heat treated at 1800C for Fig. 6(b)(1700C specimen) and Fig. 6(c)(1800C speci 5 h in an argon atmosphere. TEM investigations of the men) are very similar. More detailed information on material revealed no significant differences between this short-range ordering of the matrix phase was obtained by and the 1700C sample SiC crystal size was found to be high-resolution TEM(HRTEM). In Fig 8, a typical micro- between 37.5 and 62.5 nm with a change of aspect ratio structure is presented. In the left-hand part of the picture, for grain diameters exceeding 40 nm. An aspect ratio of the stacking faults of a polytype SiC grain are visI 1. 25 was observed for these particles. The EDPs shown in The right-hand side of the picture shows the matrix phasOne sample of 5c was also heat treated at 1800 C for 5 h in an argon atmosphere. TEM investigations of the material revealed no significant differences between this and the 1700 C sample. SiC crystal size was found to be between 37.5 and 62.5 nm with a change of aspect ratio for grain diameters exceeding 40 nm. An aspect ratio of 1.25 was observed for these particles. The EDPs shown in Fig. 6(b) (1700 C specimen) and Fig. 6(c) (1800 C speci￾men) are very similar. More detailed information on short-range ordering of the matrix phase was obtained by high-resolution TEM (HRTEM). In Fig. 8, a typical micro￾structure is presented. In the left-hand part of the picture, the stacking faults of a polytype SiC grain are visible. The right-hand side of the picture shows the matrix phase Fig. 6. Electron diffraction pattern of 5c samples thermolyzed at 1400 C/2 h/Ar and subsequently annealed at: (a) 1600 C, (b) 1700 C, and (c) 1800 C/5 h/Ar. Fig. 7. Bright field image and elemental distribution images of Si, C, and B of 5c thermolyzed at 1400 C/5 h/Ar and subsequently annealed at 1700 C/5 h/Ar. 1572 N. Bunjes et al. / Journal of Non-Crystalline Solids 353 (2007) 1567–1576