Critical parameters from electrical resistance of nickel

High-precision resistance measurements (rms relative error below 4 ×{} 10^-7 per point) for nickel around Tc are reported. When fitting the singular part of the resistance to the function Rₛ=A|t|^1-α(1+D|t|ᶻ), we obtain α=-0.095, AA^'=-1.52, $z=0.57$, and DD^'=-0.8 within the temperature region 1.6×10^-3<|t|<12×10^-3. The cause of the rounding of experimental data close to Tc is discussed.