Effects of electronic energy loss on the behavior of Nd2Zr2O7 pyrochlore irradiated with swift heavy ions

Nd2Zr2O7 pyrochlore was irradiated with swift heavy ions in order to investigate the effects of electronic energy loss on the structural changes induced in this material. XRD and TEM results show that both pyrochlore–fluorite phase transformation and amorphization occur in Nd2Zr2O7. Ion tracks are thus composed of a mixture of anion-deficient fluorite phase and amorphous zones. A new phenomenological model (heterogeneous track overlap model – HTOM), which assumes a direct impact mechanism coupled with a single track overlap process to fit the transformation build-ups, is proposed to estimate the areas of the various track regions. The variation of electronic energy loss mainly influences the structure of ion tracks (and weakly their diameter), and essentially concerns the amount of amorphous phase versus the amount of fluorite counterpart.