  Neutron diffraction, magnetic susceptibility, specific heat, and dielectric
constant measurements of single crystal Co3TeO6 have been measured to study the
interplay between the ferroelectricity and magnetic order. Long range
incommensurate magnetic order develops below TM1=26 K, which is followed by
three additional zero-field phase transitions at TM2=19.5 K, TM3=18 K, and
TM4=16 K where the incommensurate order changes and commensurate order
develops. In magnetic fields up to 14 T we find that the magnetic intensities
and incommensurate wave vector are dramatically altered as ferroelectricity
develops, with a fifth abrupt transition around 10 T. The overall behavior
characterizes Co3TeO6 as a type-II multiferroic.

Strongly Correlated Electrons