CRYSTALLIZATION OF ULTRATHIN W-SI MULTILAYER STRUCTURES BY HIGH-ENERGY HEAVY-ION IRRADIATIONS

Ultrathin amorphous multilayers structures (1.55 nm bilayer period) were irradiated by high-energy heavy ion (127I and 238U ions). Transmission electron microscopy study shows that the ion-material interaction in such a configuration leads to an irreversible transformation of the initial amorphous structures. In this letter, we report the first observation of the crystallization of the multilayers induced by the heavy ion irradiations with a subsequent formation of a new WSi structure. The crucial role of the electronic effects in the crystallization process is discussed relatively to the other phenomena induced under the ion irradiation.