The paper suggests a criterion for selection of radiation stable semiconductors and dielectrics.
The search for materials with great radiation stability (RS) is one of the basic problems in materials science. The absolute RS of crystals could be provided only in case when all elementary radiation defects (Frenkel pairs) are unstable, and annihilated immediately at any low temperatures in the places whete they were born. The presence of an instability zone (IZ) of point defects vacancy (v) - interstitial atom (i) is a necessary condition for RS [1,2]. The characteristic radius r 0 of IZ at v-i Coulomb interaction is on the order of 10-30 Å . The important parameter is a mean distance x between stopping point of atom i, knocked out from its site, and the v born at this site. Without taking into account the periodic structure, the analytical expression for x was obtained. The value of x appears to be not large. For example, if the knocked out atom has the energy of 10 keV, the mean distance between v and i is 10 Å in iron, and only 3 Å in copper (x < r 0). So, the greatest part of i's seem to remain in IZ, and therefore must recombine with “their” own v's. This would result in RS being greater than what was really observed in majority of nonmetal crystals.