Site dilution of two-dimensional honeycomb molecular ferrimagnets AFeIIFeIII(C2O4)3 (A = (n-C4H9)N, P(C6H5)4)

Abstract

The effect of site dilution on the bulk magnetic properties of two-dimensional honeycomb ferrimagnets AFe^IIFe^III(C₂O₄)₃ (A = (n-C₄H₉)₄N, P(C₆H₅)₄) has been studied by substituting the Fe^II site with Zn and the Fe^III site with Ga. In the (n-C₄H₉)₄N compounds the critical temperature T_c falls to zero at a mole fraction of diamagnetic dopant (Zn or Ga) between 0.6 and 0.65. In the P(C₆H₅)₄ compounds only 50% doping of Fe^III with Ga is needed to suppress long-range order, probably because Fe^II vacancies are already present in the lattice. Monte Carlo calculations predict the quantitative variation of T_c with dilution, but experimentally the dopant has a smaller effect than predicted, possibly because the dopant ions are not randomly distributed.