Size-dependent electrical transport properties in Co nanocluster-assembled granular films

Abstract

A series of Co nanocluster-assembled films with cluster sizes ranging from 4.5 nm to 14.7 nm were prepared by the plasma-gas-condensation method. The size-dependent electrical transport properties were systematically investigated. Both of the longitudinal resistivity () and saturated anomalous Hall resistivity () continuously increased with the decrease of the cluster sizes (d). The firstly increased and then decreased with increasing the temperature for all samples, which could be well described by involving the thermally fluctuation-induced tunneling (FIT) process and scattering. The tunneling effect was verified to result in the invalidation of classical anomalous Hall effect (AHE) scaling relation. After deducting the contribution from tunneling effect to , the AHE scaling relation between and the scattering resistivity () by varying the temperature was reconstructed. The value of scaling exponent γ increased with increasing Co cluster sizes. The size dependence of γ might be qualitatively interpreted by the interface and surface-induced spin flip scattering. We also determined the scaling relation between and at 5 K by changing the Co cluster sizes, and a large value of γ = 3.6 was obtained which might be ascribed to the surface and interfacial scattering.

Physical Vapor Deposition Cluster Arrival Energy Enhances the Electrochemical Performance of Silicon Thin-Film Anodes for Li-Ion Batteries

“…The mean diameters of the clusters were determined using ImageJ as described by Rasband . The larger cluster size associated with the best-performing film coincided with an improvement in conductivity, and this phenomenon has also been seen by Zhang et al who found that increased cluster diameters decreased film resistivity. Thus, the low electronic resistivity of the best-performing film (i.e., 7 Ω·m), coupled with an improvement in the Si cluster volume-to-surface area ratio has resulted in improved capacity retention and ICE compared to the worst-performing film (i.e., 97 kΩ·m).…”