Experimental characterization of magnetic Barkhausen noise on the strain of electroplated nickel film

The magnetic Barkhausen noise method was used to measure and characterize the tensile strain of electroplated nickel film on red copper substrate.First of all, an experimental device was built to synchronously measure the strain and magnetic Barkhausen noise signals during the tensile process of electroplated nickel film; Secondly, the tangential magnetic field intensity signals on the surface of nickel films with different thicknesses and the magnetic Barkhausen noise under different strain conditions were obtained, and the characteristic magnetic parameters sensitive to the thickness and strain of nickel films were selected from the two signals; Finally, the quantitative characterization ability of characteristic magnetic parameters to nickel film thickness and tensile strain was analyzed by equation fitting. The results showed that the amplitude of fundamental wave (A₁) of tangential magnetic field intensity decreased linearly with the increase of nickel film thickness; Dependence of the characteristic parameters of the magnetic Barkhausen noise (M_max or M_mean) on tensile strain obeyed exponential decay function. By combining the characteristic parameters of the two signals, the quantitative measurement of nickel film thickness and tensile strain can be realized.