Diffused phase transitions in Pb(Zr_0.65Ti_0.35)O₃-Pb(Fe_2/3W_1/3)O₃ multiferroics

The solid solutions of (1−x)Pb(Zr_0.65Ti_0.35)O₃-xPb(Fe_2/3W_1/3)O₃ in different ratios were fabricated by a high-temperature solid-state reaction method using high-purity oxides for possible multi-ferroic applications. Structural analysis using x-ray diffraction powder patterns of the system by Rietveld refinement method exhibits the formation of rhombohedral phase with R3c space group. Detailed studies of dielectric permittivity as a function of temperature of the systems show that the frequency independent dielectric maximum temperature shifts toward room temperature on increasing x. In addition to this, the degree of diffuseness of the permittivity anomaly is more pronounced for higher content of Pb(Fe_2/3W_1/3)O₃, implying the existence of a composition-induced diffuse phase transition for the limited range of compositional ratios. Detailed impedance spectroscopy analysis shows the contributions of grain, grain boundary, and interfacial polarizations in the resistive characteristics and conduction mechanism of the materials. The weak ferromagnetic and saturated ferroelectric loops indicate that system with x = 0.1, 0.2 have good multiferroic characteristics, and may be useful for future spintronic devices