Demagnetizing correction in fluxmetric measurements of magnetization curves and hysteresis loops of ferromagnetic cylinders.

A technique is proposed for demagnetizing correction of the measured magnetization curve and hysteresis loop, i.e., the M ∗ ( H a ) curve, of a ferromagnetic cylinder into the true M ( H ) curve of the material, where H a is the uniform applied field provided by a long solenoid and M ∗ is the magnetization measured by a fluxmeter with the measuring coil surrounding the cylinder midplane. Different from ordinary demagnetizing correction by using a fixed demagnetizing factor, an ( H a , M ∗ ) -dependent fluxmetric demagnetizing factor N f ( γ , χ d ) is used in this technique, where γ is the ratio of cylinder length to diameter, χ d is the differential susceptibility on the corrected M ( H ) curve, and N f ( γ , χ d ) is approximated by accurately calculated N f ( γ , χ ) of paramagnetic cylinders of the same γ and χ = χ d . The validity of the technique is studied by comparing results for several samples of different lengths cut from the same cylinder. Such a demagnetizing correction is unambiguous but its success requires very high accuracy in the N f determination and M ∗ ( H a ) measurements. [ABSTRACT FROM AUTHOR]