EPR of Mn2+ in the kagomé staircase compound Mg2.97Mn0.03V2O8

The electron paramagnetic resonance (EPR) of Mn2+ in geometrically frustrated Mg2.97Mn0.03V2O8 single crystals is reported. The complex EPR spectrum shows resonance lines associated with two crystallographically nonequivalent lattice positions of Mn ions that are known in the kagome staircase system as "cross-tie" and "spine" sites. Additionally, strongly anisotropic resonances of various Mn2+-Mn2+ pairs are observed. The signs and values of the crystal field parameters are determined from EPR spectra. The local magnetic symmetry details of magnetic ions and components of the hyperfine structure tensor are determined for various nonequivalent manganese positions. The exchange coupling between Mn ions in "cross-tie" and "spine" sites is found to be J=41 K.