Low field magnetoconductance studies in aggregated Al nano-clusters

Nano-aggregates of Al have been formed by 70 keV He+ irradiation on spin ca st films of aluminum acetyl acetonate. Three fold increase in conductivity was observed for a fluence, range of 1 X 10(16) -5 X 10(17) ions/cm(2). Ele ctrical transport of the charge carriers was observed to follow Mott's vari able range hopping (VRH) mechanism in 3D nano-aggregates of Al in the tempe rature regime of 110-300 gr K. Low field (less than or equal to1 T) magneto resistance (MR) studies in these samples showed change in sign of MR from p ositive for a sample with low zero field resistance [R(H=0)] to negative fo r samples with high R(H=0) owing to quantum interference phenomena of hoppi ng paths. (C) 2001 Elsevier Science B.V. All rights reserved.