Modification of icosahedral quasicrystal Al65Cu20Fe15 by 170-MeV Ni-58(+12) beam

Thin ribbons of stable icosahedral quasicrystal Al65Cu20Fe15 were irradiate d with swift heavy ion (SHI) beam of 170 million electron volt (MeV) Ni-58( +12) in high and clean vacuum environment at a temperature of 80 K to study the modification of its properties. Dynamic variation of resistance was st udied on-line during and after irradiation for the first time, to understan d the effect of SHI. The resistance decreased sharply at the time of incide nce of ion beam due to creation of a large number of charge carriers by int ense ionization by SI-H and did oscillate around a mean value during irradi ation due to defect creation and annihilation. The resistance increased rap idly just after the beam was stopped from its mean value during irradiation . The quasicrystalline peaks of the XRD data on these samples irradiated by SHI, were prominent till the ion beam fluence of 5 X 10(12) particles/cm(2 ), but the peak height consistently decreased with increasing fluence after a fluence of 1012 articles/cm(2). (C) 2001 Elsevier Science Ltd. All right s reserved.