Electrical transport phenomena and modulus behavior in lead-free Ba0.85Sr0.15Ti0.85Zr0.15O3 compound

In this work, the ceramic Ba0.85Sr0.15Ti0.85Zr0.15O3 is prepared using the conventional solid-state reaction method. The frequency dependence of the electrical conductivity, impedance, and electric modulus of Ba0.85Sr0.15Ti0.85Zr0.15O3 are investigated using numerous theoretical laws over a large temperature range. The X-ray diffraction (XRD) study confirms that this composition crystallizes in pseudo-cubic symmetry. In addition, it shows the good crystallization of our material. The appearance of semiconductor behavior is attributed to the activation of the small polaron hopping process. AC conductivity analysis confirms the presence of complex behaviors. Indeed, we found the contribution of several hopping and tunneling processes to the conduction properties. The Nyquist plots (Z” vs. Z’) confirm the important contribution of the microstructure to the transport and relaxation phenomena. The complex modulus analysis confirms the strong correlation between the movements of the mobile charge carriers and shows the thermal activation of the relaxation process in Ba0.85Sr0.15Ti0.85Zr0.15O3. As a result, the long-distance movement of the load carriers essentially determines the relaxation process at low frequencies. From the electric modulus results, it is observed that the system under study reveals a non-Debye character. •Measurements were used for electrical conductivity and electric modulus.•Nyquist plots confirm the important contribution of the microstructure.•The tunneling and hopping mechanisms were used to explain the transport process.•The electrical modulus indicated the non-Debye character of the compound.