Modification and Characterisation of Materials by Swift Heavy Ions

Swift heavy ions (SHI) available with 15 million Volt Pelletron accelerator at Inter University Accelerator Centre (IUAC) Delhi, formerly known as Nuclear Science Centre, (NSC), provide a unique opportunity to researchers for accelerator based materials science research. The major research areas can be broadly categorised as electronic sputtering, interface modifications, synthesis and modification of nanostructures, phase transitions and ion beam-induced epitaxial crystallisation. In, general, SHI irradiation based-materials may not be economically feasible, still it could be of interest for very specific cases in defence and space research. The paper gives a glimpse of the current research activities in materials science with SHIs, at IUAC.Defence Science Journal, 2009, 59(4), pp.401-412, DOI:http://dx.doi.org/10.14429/dsj.59.154

Swift Heavy Ion-induced Mixing

In this paper, the possible swift heavy ion (SHI)-matter interaction processes and their applicability to SHI-induced mixing have been discussed. The assumption that the SHI mixing is a consequence of a transient molten state diffusion has been brought forward. The following experimental evidences have been presented to verify the concepts developed for SHI mixing process: (i) Evidence of high temperature conditions in materials produced by SHIs via the study of SHI mixing in an Fe/Fe57/Si system; (ii) Verification of the hypothesis of transient molten state diffusion via a detailed study on Fe/Si system; (iii) The role played by a thermodynamical parameter, viz., interfacial free energy via a SHI mixing study on an Fe/Si multilayer; (iv) Demonstration of the occurrence of the process in an exclusively thermal-spike determined metal/metal system, viz., Fe/Ni multilayer; and (v) synthesis of technologically important SiC phases at room temperature via SHI mixing of C-allotrope/Si multilayers.Defence Science Journal, 2009, 59(4), pp.425-435, DOI:http://dx.doi.org/10.14429/dsj.59.154