(color online) Recoil loops of the (a) 550 and (b) 800 °C annealed samples with different sweep rates: (black) η = η₀ and (red) . The inset defines M_up(H), M_dw(H), and ΔM_rc(H), which are the magnetizations of the upper and lower branches, and their difference, respectively. The maximum normalized recoil loop openness in each recoil loop was then defined as , where H_R is the applied reversal field.^[265]