Evolution of the commensurate and incommensurate magnetic phases of the S = 3/2 kagome staircase Co3V2O8 in an applied field

TL;DR

This study investigates how magnetic phases in Co3V2O8 evolve under an applied magnetic field, revealing complex phase transitions and the emergence of new commensurate phases through neutron diffraction analysis.

Contribution

It provides the first detailed neutron diffraction analysis of magnetic phase evolution in Co3V2O8 under an applied magnetic field along the easy axis.

Findings

Small fields destabilize incommensurate phases.

Larger fields restore and create new commensurate phases.

Higher-order scattering indicates complex magnetic ordering.

Abstract

Single crystal neutron diffraction studies have been performed on the S = 3/2 kagome staircase compound Co3V2O8 with a magnetic field applied along the magnetization easy-axis (H || a). Previous zero field measurements [Y. Chen, et al., Phys. Rev. B 74, 014430 (2006)] reported a rich variety of magnetic phases, with a ferromagnetic ground state as well as incommensurate, transversely polarized spin density wave (SDW) phases (with a propagation vector of k = (0 delta 0)) interspersed with multiple commensurate lock-in transitions. The magnetic phase diagram with H || a adds further complexity. For small applied fields, H = 0.05 T, the commensurate lock-in phases are destabilized in favor of the incommensurate SDW, while slightly larger applied fields restore the commensurate lock-in phase with delta = 1/2 and yield a new commensurate phase with delta = 2/5. For all measurements in an applied field, higher-order scattering is observed that corresponds to the second-harmonic.