Kagome staircase compound Co3V2O8 in an applied magnetic field: single-crystal neutron-diffraction study

摘要

The magnetic properties of Co3V2O8 have been studied by single-crystalneutron-diffraction. In zero magnetic field, the observed broadening of themagnetic Bragg peaks suggests the presence of disorder both in thelow-temperature ferromagnetic and in the higher-temperature antiferromagneticstate. The field dependence of the intensity and position of the magneticreflections in Co3V2O8 reveals a complex sequence of phase transitions in thisKagome staircase compound. For H//a, a commensurate-incommensurate-commensuratetransition is found in a field of 0.072 T in the antiferromagnetic phase at 7.5K. For H//c at low-temperature, an applied field induces an unusualtransformation from a ferromagnetic to an antiferromagnetic state at about 1 Taccompanied by a sharp increase in magnetisation.