  An extensive low temperature magnetisation study of high quality single
crystals of the Kagome staircase compounds Ni3V2O8 and Co3V2O8 has been
performed, and the H-T phase diagrams have been determined from these
measurements. The magnetisation and susceptibility curves for Co3V2O8 are
analysed in terms of their compatibility with the different ferromagnetic and
antiferromagnetic structures proposed for this compound. For Ni3V2O8, the phase
diagram is extended to magnetic fields higher than previously reported; for a
field applied along the a-axis, the low temperature incommensurate phase is
found to close at around 90 kOe.
