Vibrational studies, dielectric, and electrical conductivity in (Ba0.95Ca0.05)0.1(Ti0.8Sn0.2)0.1Na0.9Nb0.9O3 ferroelectric ceramic

(Ba0.95Ca0.05)0.1(Ti0.8Sn0.2)0.1Na 0.9Nb0.9O3 (BCNTSNO3) ferroelectric ceramic was synthesized by traditional solid-state method. Room temperature structural analysis, using X-ray diffraction data, confirmed the prepared ceramic purity with the existence of morphotropic phase boundary (MPB) which appears from tetragonal to orthorhombic symmetry with P4mm and Pmm2 space group, respectively. Temperature dependence of the dielectric measurement exhibited a ferroelectric–paraelectric transition at 540 K. Raman spectra were studied in the range of 50–1000 cm−1 as a function of temperature of 293 K–573 K. A detailed analysis of the frequency and half-width versus temperature introduces huge changes which are associated to the ferroelectric transitions originating from the internal vibrational modes of NbO6 octahedron. Electrical conductivity was carried out, using impedance spectroscopy, in the frequency and temperature range, 1 Hz–1 MHz and 500–600 K, respectively. Both impedance and modulus analysis exhibit the contribution of grain and grain boundary to the sample electrical response. To explain the impedance results, an equivalent circuit was proposed. The temperature dependence of the alternating current conductivity (σac) and characteristic relaxation time (τ) confirmed the observed ferroelectric phase transitions in the dielectric study. Moreover, temperature dependence of frequency exponent (s) is investigated to explain the conduction mechanism in the different regions. It was attributed to the correlated barrier-hopping model (CBH) in region (I) and (II).