Anomalies in growth of electrodeposited Ni–Fe nanogranular films

T. I. Zubar, L. V. Panina, N. N. Kovaleva, S. A. Sharko, D. I. Tishkevich, D. A. Vinnik, S. A. Gudkova, E. L. Trukhanova, E. A. Trofimov, S. A. Chizhik, S. V. Trukhanov, A. V. Trukhanov

Index: 10.1039/C8CE00310F

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Abstract

Thin Ni–Fe films were produced via electrodeposition onto silicon substrates using direct current and pulse current (with different pulse durations) regimes. The correlation between the technological regimes, chemical composition and microstructure of Ni–Fe nanogranular films was investigated. Analysis of the microstructure evolution revealed that the mechanism of film growth changes from Volmer–Weber (island film growth) to Stranski–Krastanov (layer by layer growth) with the shortening of the pulse duration below 10 μs. This anomalous behavior was explained by the increase of the binding energy between the initial film atoms and the substrate surface. The results showed that using electrodeposition regimes, which ensure growth with an average crystal size less than the critical value of 10 nm, provides less roughness and defectiveness and better film uniformity in thickness.