Determination of external and internal demagnetizing factors for strip-like amorphous ribbon samples

• Published in: Journal of magnetism and magnetic materials 2020-08, Vol.507, p.166845, Article 166845
• Main Authors: Varga, Lajos K., Kováč, Josef, Novák, Ladislav
• Format: Article
• Language: English
• Subjects: Anhysteretic curve; Coercive field; Demagnetization; Diameters; Effective anisotropy energy; External; Ferrous alloys; Internal and effective demagnetizing factor; Lower bounds; Mathematical analysis; Slopes; Strip; Thickness ratio
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2020.166845

•Power law fitting for geometrical demagnetizing factor data determined on rod like samples.•Splitting the experimental demagnetizing factor in external and internal ones.•Calculating the effective width of the strip and of the internal demagnetizing factor.•Lower bound for the internal demagnetizing factor determined experimentally. The extension of results concerning the calculation of the external (geometric) demagnetizing factor obtained for rod like samples to strip-like ribbon samples is investigated. To match the experimental determined demagnetizing factors of strips with various length two fitting parameters have been introduced: (i) the effective width of the strip and (2) the internal demagnetizing factor. It turned out that the equivalent rod diameter calculation from the cross-section is valid up to a limited width/thickness ratio. The experimental demagnetizing factor determined from the steepness of the anhysteretic curve was greatly reduced by a uniaxial stress; where from a lower bound for the internal demagnetizing factor could be obtained. We have found that this internal demagnetizing factor is about three times larger than the geometric one for an as cast amorphous sample with Finemet composition.