Surface magnetic field evolution for LM (left panel) and HM (right panel) models for two different values of the initial magnetic field expulsion: at ρ_i = ρ_CC ≈ 1.3 × 10¹⁴ gr cm^-3 (solid lines) and at ρ_i = ρ_ND = 4.2 × 10¹¹ gr cm^-3 (dashed lines). Two extreme accretion scenarios are compared: Ṁ_-10 = 5, for a high accretion rate, and Ṁ_-10 = 0, for no accretion (purely diffusive case). Here we set Q = 5.0 and no SF case.