“…In this region, both fields are of comparable magnitude. A similar behavior has been previewed in the systems called ''weak ferrimagnets'' which consist on two coupled paramagnetic sublattices [25,26]. Moreover, this feature has been revealed experimentally within the lamellar oxides LiNi x Co 1Àx O 2 (0:5p xp 1) which can be regarded as a mixed-spin ( 1 2 ; 1) systems for respectively Co 2þ and Ni 2þ [27].…”