Approximation of the influence of effective magnetic parameters on the coercivity of iron-based nanocrystalline films

The magnetization curves and hysteresis loops of Fe, Fe$_{90}$N$_{10}$, Fe$_{95}$Zr$_{5}$, Fe$_{85}$Zr$_{5}$N$_{10}$, Fe$_{77}$Zr$_{7}$N$_{16}$ films were measured for determining coercive field $H_c$, saturation magnetization $M_s$, and the rms fluctuation of local magnetic-anisotropy field $a^{1/2}H_{a}$ of these iron-based materials. A model approximation with empirical second-order polynomial and Pareto chart clearly demonstrates the influence of the grain size, anisotropy field $a^{1/2}H_{a}$, and saturation magnetization on the coercive field.