Evaluation of the effects of pulsed magnetic field treatment as a nondestructive treatment for magnetic materials

Pulsed magnetic treatment has been suggested as a nondestructive treatment of magnetic materials for reducing microscopic stress and strain in the materials. Systematic studies have been made to test the effect of pulsed magnetic field treatments in a variety of magnetic materials including bulk nickel and magnetic thin film samples. The treatment involves the application of a low frequency, periodic magnetic field superimposed with a high frequency pulse component followed by demagnetization. Equipment for applying the pulsed magnetic field treatment has been designed and constructed, together with computer software which was developed to allow complete control of the waveform, frequency and amplitude of the pulsed magnetic field profile. Various characterization techniques, including magnetic hysteresis, Barkhausen effect measurements and magnetic force microscopy, were used to test the effects of the pulsed magnetic field treatment. Present results indicate that the stress relief effect of the treatment on the samples, if there is any, is much weaker than claimed in previous studies.