Radiation enhanced sublimation of boron containing carbon materials

Thye radiation enhanced sublimation (RES) of boron containing graphites as well as amorphous boron containing carbon films (a-C/B:H films) has been investigated with the result that it cannot be completely suppressed. However, the onset temperature for RES is shifted to higher values compared to carbon resulting in a reduced yield in a limited temperature range to about 1800 K. The reduction of RES of boron containing carbon materials depends on the boron content as well as on the microstructure of the bulk material. Above 1800 K, the thermal sublimation of boron leads to a recovery of RES up to values as observed for pure carbon. (orig.)