Peter Reis, University of North Dakota and Oak Ridge National Laboratory
Bimetallic oxalates are layered organic magnets which exhibit the possibility of magnetic compensation (MC) when their ground state is ferrimagnetic. As shown for Fe(II)Fe(III) ferromagnetic compounds the magnetization changes sign at a compensation temperature Tcomp below the ferromagnetic transition temperature Tc. In an effort to see if MC is possible in other bimetallic oxalates, we model oxalates which have been synthesized and reported to have antiferromagnetic exchange interactions. We use symmetry arguments to construct the crystal field potential, and include the spin-orbit coupling on both metal ions and the magnetic exchange between them. By allowing the orbital angular momentum of the metal ions to vary from being completely quenched to unquenched we show that regions of MC exist in the isostructural compounds M(II)Mn(III) M=Fe,Co,Ni and V(II)M'(III) M'=Cr, V; while it is absent in M(II)Ru(III) M=Fe, Cu.