Interplay between the magnetic and electric degrees-of-freedom in   multiferroic Co3TeO6
  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. 
Wen-Hsien Li, Chin-Wei Wang, Daniel Hsu, Chi-Hung Lee, Chun-Ming Wu,   Chih-Chieh Chou, Hung-Duen Yang, Yang Zhao, Sung Chan...
cond-mat.str-el