Ion-induced change in Vickers hardness and arm length of dislocation rosettes

created by indentation on the (100) face of LiF crystals was studied. The

irradiations were performed using swift U, Bi and Ni ions with a specific energy of

11MeV per nucleon at fluences between 106 and 1013/cm2. Remarkable effects of

the ion-induced hardening and reduction of dislocation arm length were observed above the threshold fluences of 109 to 1010/cm2 and 106 to 107/cm2, respectively.

The products of track core damage and aggregates of single defects in the halo of

overlapping tracks were responsible for the effects. The results were analysed using

the Orowan's model of dislocation impeding by strong obstacles. The advantages

of the dislocation mobility method for the diagnostics of track damage at lowfluence

irradiations were demonstrated.

Swift-Ion-Induced Hardening and Reduction of Dislocation Mobility in LiF

Crystals. I.Manika, J.Maniks, K.Schwartz: Journal of Physics D, 2008, 41[7],

074008