Fig. 4: Pt/Co/MgO structure with easy-cone state.

a Magnetic phase diagram in the \(K_1^{{\mathrm{eff}}}\)−K₂ plane, with the \(K_1^{{\mathrm{eff}}}\)and K₂ values indicated at several t_Co values in nanometers. b Plot of θ_c vs. t_Co. The error bars of \(K_1^{{\mathrm{eff}}}\), K₂, and θ_c were obtained from three repeated measurements.