FRUSTRATED MAGNETISM IN A KAGOMÉ STAIRCASE LATTICE
Joel S. Helton and Jeffrey W. Lynn
NIST Center for Neutron Research
Co3V2O8 displays S=3/2 moments arrayed geometrically frustrated kagomé staircase lattice. The geometric frustration of the antiferromagnetic kagomé lattice is partially lifted by further-neighbor interactions. This combination of geometric frustration and competing interactions yields a complex phase diagram: an incommensurate antiferromagnetic order that arises below T = 11.3 K evolves and displays two commensurate lock-in phases before entering the ferromagnetic ground state below T = 6.2 K. Neutron diffraction experiments with small magnetic fields applied parallel to the easy axis yield a new, distinct commensurate antiferromagnetic phase with a propagation vector of (0 0.4 0). Critical scattering near the incommensurate-to-paramagnetic phase transition is also explored.