Impedance spectroscopy and permittivity study of (1-x)NBT-xBT ceramics

Abstract

The complex impedance spectroscopy method was applied to evaluate the profound characteristics of the electrical transport capacity of lead-free ferroelectric ceramic solid solutions of (1-x)(Na 0.5 Bi 0.5 )TiO 3-x Ba TiO 3 (NBT-xBT) (0.00 ≤ x ≤ 0.10). The elaboration of NBT-xBT, via a solid-state reaction between (Na 0.5 Bi 0.5 )TiO 3 and BaTiO 3 , was determined using X-ray diffraction. Refinements, at room temperature, identified a rhombohedral phase, space group R3c for x = 0.0 and 0.03, which possesses an antiphase, corresponding to the tilting system ā ā ā with an angle of inclination of 8.24° according to Glazer's notation. We used the complex impedance, complex electric Cole-Cole diagram and frequency-dependent AC conductivity analysis to examine the relaxation and conduction mechanism in these samples, which exhibit non-Debye type behaviour. In addition, using an equivalent circuit composed of resistance and capacitance, we examined the different contributions (grains and grain boundaries) in our samples. (Na 0.5 Bi 0.5 )TiO 3 exhibits a dielectric resonance, which manifests itself as negative permittivity. The resonance development of NBT-xBT in the range (500 Hz − 2 MHz) is discussed in this paper.

(1-x)(Na₀.₅Bi₀.₅)TiO₃-xCaTiO₃ ceramics: Investigating structural and microstructural features for enhanced dielectric properties

“…This trend is attributed to the prevalence of various defects and oxygen vacancies at the grain boundaries. Perovskite materials, in general, demonstrate enhanced conductivity primarily due to these oxygen vacancies [ 19 , 42 ]. Commonly, the sintering process facilitates the volatilization of A-site cations, leading to the formation of oxygen vacancies [ 9 ].…”

“…The electrical properties of NBT-based materials are enhanced principally through phase boundary engineering and optimization of the preparation procedure [ [15] , [16] , [17] ]. In specific, (1- x )NBT- x BT and (1- x )NBT- x CT systems materials have been regarded as one of the most promising lead-free ferroelectric compounds [ 18 , 19 ]. Subramani et al investigated the influences of tetragonal CaTiO 3 (CT) addition on the sintering, properties, microstructures, and characteristics of (Na 0.5 Bi 0.5 )TiO 3 (NBT) materials, and inferred that a little BT is advantageous for enhancing the dielectric performance of NBT materials [ 20 ].…”

Study on the Structure, Morphology, Dielectric, and Piezoelectric Properties of Large-Grain (Ba0.85Sr0.15)1–xPbxTiO3 Ceramic System for 0.02 ≤ x ≤ 0.08

“…This dynamic unveils the presence of charged entities (such as oxygen vacancies or grain boundary effects) that face constraints in tracking the fluctuations of the alternating electric field, especially at higher frequencies. 66,67 With an increase in temperature, there is a reduction in the amplitude of the dielectric constant. This decrease can be attributed to the temperature-induced misalignment of corresponding dipoles.…”

DIELECTRIC MEASUREMENTS AND IMPEDANCE SPECTROSCOPY OF Ba-MODIFIED (Na 0.5Bi0.5)TiO₃ PREPARED BY THE HYDROTHERMAL METHOD

“…Sodium bismuth titanate, (Na 0.5 Bi 0.5 TiO 3 ; (NBT), has been proposed as a potential candidate for lead-free piezoelectric ceramics based on its excellent ferroelectricity at ambient temperature. [1,2,3,4] Sodium bismuth titanate is characterised by having a rhombohedral perovskite structure with (a = 5,4884 Å and c = 13,5045 Å). [5,6] Relaxor ferroelectric materials represent a special class of disordered structures exhibiting a particular structure and properties.…”