Effect of Zr substitution on structural and dielectric properties of Pb5EuTi3−xZrxNb7O30 (x=0, 1, 2 and 3) ferroelectric ceramics

The polycrystalline samples of Pb₅EuTi_3–xZr_xNb₇O₃₀ (x=0, 1, 2 and 3) were prepared by a high-temperature solid-state reaction technique. Formation of the compounds was checked by X-ray diffraction method. All the compounds were found to have orthorhombic structure at room temperature. Studies of their dielectric constant (e) as a function of temperature (25–375 °C) at 10 kHz exhibit ferroelectric phase transition of a diffuse-type. With increasing Zr concentration (x), transition temperature (T_c) as well as dielectric constant decreases. Temperature variation of d.c. resistivity/conductivity shows that these compounds exhibit negative temperature coefficient of resistance in the high temperature range.