ABSTRACT
We present the results of magnetization and AC susceptibility measurements performed on ferrimagnetic Mn(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O and ferromagnetic Ni(3)(2+)[Cr(III)(CN)(6)](2)·12H(2)O systems under pressures up to 0.9 GPa in a commercial SQUID magnetometer. The magnetization process is affected by pressure: magnetization saturates at higher magnetic field, saturated magnetization µ(s) of Ni(3)[Cr(CN)(6)](2) is reduced and almost unaffected for Mn(3)[Cr(CN)(6)](2) at low temperatures. The Curie temperature T(C) of Mn(3)[Cr(CN)(6)](2) increases with the applied pressure, ΔT(C)/Δp = 25.5 K GPa(-1), due to a strengthened super-exchange antiferromagnetic interaction J(AF), but it is not affected significantly in the case of Ni(3)[Cr(CN)(6)](2) with a dominant ferromagnetic J(F) super-exchange interaction. The increase in the J(AF) interaction is attributed to the enhanced value of the single electron overlapping integral S and the energy gap Δ of the mixed molecular orbitals t(2g) (Mn(2+)) and t(2g) (Cr(III)) induced by pressure.