Synthesis, structure and properties of the magnetic relaxor ferroelectric Pb(Fe_2/3W_1/3)O₃ [PFW]

Single crystals of Pb(Fe_2/3W_1/3)O₃ [PFW] have been grown from high temperature solution using (PbO-B₂O₃) flux. The crystal structure of PFW shows a B-site Fe/W disorder and a positional disorder due to atomic shifts. The dielectric properties indicate relaxor ferroelectric behavior with a dispersive maximum of permittivity at T_m (from 178 K at 1 kHz to 190 K at 1 MHz). A macropolar phase can be induced by application of an electric field, leading to the induced ferroelectricity. The temperature dependence of the magnetization reveals two magnetic phase transitions at T_N1 = 350 K and T_N2 = 20 K, resulting from the microstructural features of the complex perovskite, characterized by B-site disordered and ordered clusters.