title: Spin waves in antiferromagnetically coupled bimetallic oxalates.
abstract: Bimetallic oxalates are molecule-based magnets with transition-metal ions M(II) and M(')(III) arranged on an open honeycomb lattice. Performing a Holstein-Primakoff expansion, we obtain the spin-wave spectrum of antiferromagnetically coupled bimetallic oxalates as a function of the crystal-field angular momentum L(2) and L(3) on the M(II) and M(')(III) sites. Our results are applied to the Fe(II)Mn(III), Ni(II)Mn(III) and V(II)V(III) bimetallic oxalates, where the spin-wave gap varies from 0 meV for quenched angular momentum to as high as 15 meV. The presence or absence of magnetic compensation appears to have no effect on the spin-wave gap.
authors.affiliation: Physics Department, University of North Dakota, Grand Forks, ND 58202-7129, USA. Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6065, USA.
authors.forename: Peter L
authors.initials: PL
authors.lastname: Reis
authors.forename: Randy S
authors.initials: RS
authors.lastname: Fishman