Monte Carlo simulation is used to study the magnetic properties and critical behaviour of a molecular-based magnetic film AFe IIFe III(C 2O 4) 3(A=N(n-C nH 2n+1) 4, n=3-5). The effects of surface exchange coupling, surface single-ion anisotropy and layer thickness on the compensation temperature and critical temperature of a ferrimagnetic mixed spin-2 and spin-5/2 Ising model on a honeycomb lattice are discussed in detail. The results show that the surface intralayer exchange coupling R 1=J 1S/J 1 and surface interlayer exchange coupling R 2=J 2S/J 1 play important roles in the compensation and critical behaviour of the system. In particular, we have found two special points R 1c at which the compensation and critical temperatures are independent of the layer thickness L and the surface single-ion anisotropy D 1S/J 1. A number of characteristic phenomena, such as the possibility of two and three compensation points, are found. The effects of the layer thickness L on the susceptibility, internal energy and specific heat with temperature are numerically investigated.
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