title: Anomalous electrical transport behavior in nanocrystalline nickel.
abstract: We have prepared nanocrystalline Ni (n-Ni) samples of grain sizes 40-100 nm using a polyol method and investigated the electrical transport on their compacted pellets in the temperature range 3-300 K. The resistivity, ρ, decreases nearly linearly with increase in compaction pressure but without a change in its slope, dρ/dT. ρ is anomalously large, and is strongly temperature and grain-size dependent. The resistivity at room temperature, ρ(300 K), is in the range ∼40-759 µΩ cm but with a positive coefficient of resistivity α (metallic). This is associated with the significantly enhanced dρ/dT with increase in residual resistivity ρ(0). These characteristics are attributed to the disorder in the grain boundaries that represents effectively a series resistor network.
authors.affiliation: UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore 452017, MP, India.
authors.forename: G S
authors.initials: GS
authors.lastname: Okram
authors.forename: Ajay
authors.initials: A
authors.lastname: Soni
authors.forename: R
authors.initials: R
authors.lastname: Rawat