CROSS-SECTIONAL TRANSMISSION ELECTRON-MICROSCOPY STUDY OF 1.5 MEV KR-INDUCED AMORPHIZATION IN ALPHA-QUARTZ( IRRADIATION)

Cross-sectional and high-resolution transmission electron microscopy ( XTEM and HRTEM, respectively) have been used to characterize ion-beam- induced amorphization of alpha-quartz irradiated with 1.5 MeV Kr+ ions at room temperature. The accumulation of damage and the growth of the amorphous layers in quartz were studied as a function of ion fluence up to 1.7 x 10(14) ions/cm(2). An amorphous band was first observed at the peak displacement damage range, and this region increased in widt h with increasing ion fluence. These results demonstrate that direct d isplacement damage by nuclear collision is more efficient than ionizat ion processes in inducing amorphization in quartz. At lower fluences ( less than or equal to 1.7 x 10(13) ions/cm(2)), the damage profile obs erved by XTEM is in excellent agreement with the distribution of displ acement damage predicted by TRIM calculations. At higher fluences, the range of the amorphous band measured by XTEM exceeds the depth predic ted by TRIM. (C) 1998 American Institute of Physics. [S0021-8979(98)09 920-4].