Criteria for saturated magnetization loop

• Proper estimation of hysteresis-loop parameters is vital in magnetic studies.
• We propose criteria for discrimination minor from major hysteresis loops.
• The criteria analyze magnetization, remanence and ZFC/FC curves and/or their derivatives.
• Examples of their application on real nanoparticles systems are given.
• Using the criteria could avoid twofold or bigger saturation-field underestimation errors.

Proper estimation of magnetization curve parameters is vital in studying magnetic systems. In the present article, criteria for discrimination non-saturated (minor) from saturated (major) hysteresis loops are proposed. These employ the analysis of (i) derivatives of both ascending and descending branches of the loop, (ii) remanent magnetization curves, and (iii) thermomagnetic curves. Computational simulations are used in order to demonstrate their validity. Examples illustrating the applicability of these criteria to well-known real systems, namely Fe3O4 and Ni fine particles, are provided. We demonstrate that the anisotropy-field value estimated from a visual examination of an only apparently major hysteresis loop could be more than two times lower than the real one.