Figure 5.

(a) Field dependence of critical current density J_s (J_c), glassy exponent μ, and barrier energy U₀. μ and U₀ are directly obtained through Eq. (2) fitting of the original measured M(t > 50 s) data. J_c is calculated from M_c obtained in Eq. (2) fitting. μ_fit is obtained from the method in Fig. 4(c). The characteristic fields were also noted in the figure. (b) Vortex phase diagram of Ca_0.8La_0.2Fe_0.978Co_0.022As₂ with various characteristic H(T). The color contour represents the critical current density J_s as functions of temperature and field. H_c2 values are obtained from temperature-dependent resistivity curves under different magnetic fields using the criterion of 90% ρ_n (data shown in SI, Fig. S5). The irreversibility field H_irr is obtained by extrapolating J_s to zero in the J_s^1/2 vs. H curves. The solid and dash lines are guide to the eye.