Molecular field calculations of the phase diagram in PrCo₂Si₂

PrCo₂Si₂ has a collinear antiferromagnetic structure with a wave vector Q₁ = (0, 0, 1) for T < T₁ = 9 K, a high-order commensurate one with Q₂ = (0,0,25/27) for T₁ ≤ T < T₂ = 17 K and with Q₃ = (0,0,7/9) for T₂ ≤ T < T_N = 30 K. Molecular field calculations of the moment arrangements and magnetization processes of the compound were made with a molecular field model, and the field-temperature magnetic phase diagram was reproduced. The magnetic transitions are discussed in connection with the wave-dependent molecular field coefficients of the compound.