Pb3TeCo3V2O14: A Potential Multiferroic Co Bearing Member of the Dugganite Series

Polycrystalline Pb3TeCo3V2O14, a structural analogue of the multiferroic Ba3NbFe3Si2O14, was synthesized and characterized using X-ray diffraction, magnetic susceptibility, specific heat, dielectric constant, and neutron diffraction. Magnetic susceptibility, specific heat capacity measurements, and bond valence analysis confirmed that the V5+ ion is nonmagnetic, while Co2+ is in its high spin state (S = 3/2). Two magnetic transitions were seen at T N1 = 8.6 K and T N2 = 6.0 K where the spins first adopt a magnetic structure with propagation vector k⃗ = (0.752,0,1/2) and reorder into a commensurate structure with propagation vector k⃗ = (5/6,5/6,1/2). Changes in the dielectric constant at both magnetic phase transitions suggest that magnetoelectric coupling exists in Pb3TeCo3V2O14.