Patent ID: 8906216

Claim:
A method for depositing a binary nickel and tungsten alloy, comprising the steps of: a. providing a liquid comprising dissolved species of at least nickel and tungsten; b. providing a first electrode and a second electrode in the liquid, coupled to a power supply configured to supply electrical potential having periods of positive polarity current and negative polarity current at different times; and c. driving the power supply with a non-constant electrical potential having a positive polarity current and a negative polarity current at different times to deposit the alloy on a substrate, wherein the alloy is a binary nickel and tungsten alloy, and the atomic percentage of tungsten in the alloy is less than about 27%, wherein a Polarity Ratio is defined by the absolute value of the time integrated amplitude of negative polarity current across all periods of negative polarity current divided by the absolute value of the time integrated amplitude of positive polarity current across all periods of positive polarity current, and wherein an average grain size of the alloy is nanocrystalline and the Polarity Ratio is selected to be between 0 and 0.225 when depositing the alloy.