Microstructure and electrical transport properties of pulse-plated nanocrystalline nickel electrodeposits

• Published in: Surface & coatings technology Vol. 88; no. 1; pp. 57 - 65
• Main Authors: Tóth-Kádár, Enikő, Bakonyi, Imre, Pogány, Lajos, Cziráki, Ágnes
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 1997; Elsevier
• Subjects: Applied sciences; Electrical transport; Exact sciences and technology; Metallic coatings; Metals. Metallurgy; Nanocrystalline nickel; Production techniques; Pulse-plated nickel; Surface treatment; Pulse-plated nickel; Electrical transport; Nanocrystalline nickel; Grain size; Pulsed current; Electrical conductivity; Electrical properties; Surface treatment; Temperature coefficient; Metal coating; Thermoelectric power; Electrodeposition; Nickel; Copper; Microstructure; Nanocrystal
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(96)02896-4

The microstructure and the electrical transport properties (the electrical resistivity, its temperature coefficient and the thermoelectric power) were investigated for pulse-plated nanocrystalline nickel electrodeposits. Transmission and scanning electron microscopy were used to study the microstructure (grain size and lattice defects) and the surface morphology respectively. The samples were prepared from the same bath as used previously for d.c. plating and the deposition current density was constant, in most cases i dep = 20 A dm −2. In a given series, the pulse length t on was kept constant at 0.001, 0.01, 0.1, 1 or 10 s and the separation between pulses toff was varied from 0.001 s to 10 s. Systematic variations of the electrical transport parameters with t on and t off were observed, which we attempt to explain in terms of the periodic variation due to pulse-plating of the local Ni 2+ concentration at the cathode-electrolyte interface.