Quantification of the Interaction Field in Arrays of Magnetic Nanowires from the Remanence Curves

Abstract

A method is presented that allows quantifying the average value of the interaction field in arrays of magnetic nanowires from the field difference between the isothermal remanence (IRM) and the DC demagnetizing (DCD) remanence curves when the normalized magnetization is equal to one third. Arrays of magnetic nanowires of different diameters and packing fractions are used to experimentally test the method. The results have been compared with those obtained using the method based on the difference between the remanence coercivity fields and with a mean-field expression for the interaction field, providing a very good agreement and thus validating the method. Additionally, it is shown that both the position (m0) and the shift along the magnetization axis of the intersection between the remanence curves with respect to the value of one third (δm = m0 − 1/3) provide qualitative information about the interaction field. The former indicates the type of interaction depending if the intersection is above (m0 > 1/3) or below (m0 < 1/3), which corresponds to a ferro or anti-ferro magnetic interaction, respectively. While for the latter, it is shown that the maximum deviation of the Delta-M plot from zero (ΔMmax) corresponds to three times the shift (ΔMmax = 3δm).