The room temperature electrodeposition of high purity, nanocrystalline Ni films prepared
in the presence of poly-(2-ethyl-2-oxazoline) (PEOX) as a new multipurpose polymeric
additive in Watts bath is presented. The grain size, morphology, hardness and magnetic
property of the nickel films were simply tuned by adjusting the concentration of PEOX.
Increasing PEOX concentration contributed to grain refinement down to 12.5 nm grain
size and crystalline orientation towards (220) planes. The control over the crystalline
grain size and the orientation by PEOX concentration allows the preparation of tailor
made nickel layers with adjustable physical and chemical properties. The effect of
PEOX on the structure is attributed to the high affinity of tertiary amide groups
in PEOX for metal surfaces, whereas the incorporation of the macromolecular additive
into the nickel layers was prevented. These findings are especially important in emerging
applications where smooth, high purity nanocrystalline layers are required. PEOX as
a multifunctional additive eliminates the need to use multiple electrolyte additives
to obtain a set of desirable properties.
