Magnetic and multiferroic phases of single-crystalline Mn$_{1-x}$Co$_{x}$WO$_{4}$

The recent interest of MnWO$_{4}$ system is due to the strong correlation between the long-wavelength magnetic structure and the ferroelectric polarization. To understand the effects of Co substitutions on magnetic and multiferroic phases of MnWO$_{4}$, we studied the magnetic and dielectric properties of the single-crystalline Mn$_{1-x}$Co$_{x}$WO$_{4}$ compounds. At lower Co substitution, the commensurate (CM) AF1 phase was found suppressed but could be restored in external magnetic fields along b axis. We also observed the ferroelectric polarization along b axis suppressed by a b-axis magnetic field. On the other hand, the higher Co substitution such as 15{\%} showed more complex magnetic phases, which warrants future investigation. With Neutron scattering data, more detailed magnetic orders of the various phases would be revealed, and the relationship between magnetic phases and ferroelectric polarization will be discussed.