The complex multiferroic phase diagram of Mn${}_{1-x}$Co${}_x$WO${}_4$

Abstract

The complete magnetic and multiferroic phase diagram of Mn${}_{1-x}$Co${}_x$WO${}_4$ single crystals is investigated by means of magnetic, heat capacity, and polarization experiments. We show that the ferroelectric polarization $\overrightarrow{P}$ in the multiferroic state abruptly changes its direction twice upon increasing Co content, x. At x${}_{c1}$=0.075, $\overrightarrow{P}$ rotates from the $b-$axis into the $a-c$ plane and at x${}_{c2}$=0.15 it flips back to the $b-$axis. The origin of the multiple polarization flops is identified as an effect of the Co anisotropy on the orientation and shape of the spin helix leading to thermodynamic instabilities caused by the decrease of the magnitude of the polarization in the corresponding phases. A qualitative description of the ferroelectric polarization is derived by taking into account the intrachain ($c-$axis) as well as the interchain ($a-$axis) exchange pathways connecting the magnetic ions. In a narrow Co concentration range (0.1$\le$x$\le$0.15), an intermediate phase, sandwiched between the collinear high-temperature and the helical low-temperature phases, is discovered. The new phase exhibits a collinear and commensurate spin modulation similar to the low-temperature magnetic structure of MnWO${}_4$.

arXiv comment18 pages, 6 figures

References in corpus (18)

• Spin current and magneto-electric effect in non-collinear magnets
• Ferroelectricity in spiral magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Magnetic inversion symmetry breaking and ferroelectricity in TbMnO3
• Magnetically driven ferroelectric order in Ni${}_3$V${}_2$O${}_8$
• Ferroelectric polarization flop in a frustrated magnet MnWO${}_4$ induced by magnetic fields
• Correlation between spin helicity and electric polarization vector in quantum-spin chain magnet LiCu${}_2$O${}_2$
• Impurity-doping induced ferroelectricity in frustrated antiferromagnet CuFeO2
• Pressure induced enhancement of ferroelectricity in multiferroic $R$Mn${}_2$O${}_5$($R$=Tb,Dy, and Ho)
• Long-Range Magnetic Interactions in the Multiferroic Antiferromagnet $\mathrm{MnW}{\mathrm{O}}_4$
• Robust Ferroelectric State in Multiferroic Mn${}_{1-x}$Zn${}_x$WO${}_4$
• Effect of nonmagnetic substituents Mg and Zn on the phase competition in the multiferroic antiferromagnet MnWO4
• The Suppression and Recovery of the Ferroelectric Phase in Multiferroic $MnW{O}_4$
• Pressure-Temperature Phase Diagram of Multiferroic $N{i}_3{V}_2{O}_8$
• Thermal expansion and pressure effect in MnWO4
• Pressure-induced polarization reversal in multiferroic $YM{n}_2{O}_5$
• Magnetic and multiferroic phases of single-crystalline Mn${}_{0.85}$Co${}_{0.15}$WO${}_4$
• Field-induced continuous rotation of the polarization in multiferroic Mn${}_{0.95}$Co${}_{0.05}$WO${}_4$

Cited by in corpus (5)

• Magnetic orders and spin-flop transitions in the cobalt doped multiferroic $\mathrm{M}{\mathrm{n}}_{1-\mathrm{x}}\mathrm{C}{\mathrm{o}}_{\mathrm{x}}\mathrm{W}{\mathrm{O}}_4$
• Magnetic field-induced spontaneous polarization reversal in multiferroic Mn${}_{0.85}$Co${}_{0.15}$WO${}_4$
• Magnetoelectric coupling tuned by competing anisotropies in Mn${}_{1-x}$Ni${}_x$TiO${}_3$
• Pressure effects on magnetic ground states in cobalt doped multiferroic Mn${}_{1-x}$Co${}_x$WO${}_4$
• Single-crystal investigations on the multiferroic material LiFe(WO${}_4$)${}_2$