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arXiv · 0802.2494

Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions

P. K. Kuiri·B. Joseph·H. P. Lenka·G. Sahu·J. Ghatak·D. Kanjilal·D. P. Mahapatra
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Abstract

Two exponents, $δ$, for size distribution of $n$-atom clusters, $Y(n)\sim n^{-δ}$, have been found in Au clusters sputtered from embedded Au nanoparticles under swift heavy ion irradiation. For small clusters, below 12.5 nm in size, $δ$ has been found to be 3/2, which can be rationalized as occurring from a steady state aggregation process with size independent aggregation. For larger clusters, a $δ$ value of 7/2 is suggested, which might come from a dynamical transition to another steady state where aggregation and evaporation rates are size dependent. In the present case, the observed decay exponents do not support any possibility of a thermodynamic liquid-gas type phase transition taking place, resulting in cluster formation.

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P. K. Kuiri, B. Joseph, H. P. Lenka, G. Sahu, J. Ghatak, D. Kanjilal, D. P. Mahapatra. 2009-10-16. Observation of a Universal Aggregation Mechanism and a Possible Phase Transition in Au Sputtered by Swift Heavy Ions. https://doi.org/10.1103/physrevlett.100.245501

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