Studies of phase transition and impedance behavior of Ba(Zr, Ti)O₃ ceramics

Abstract

Ceramic samples of Barium Zirconium Titanate (BaZr x Ti 1Àx O 3 (BZT)) were synthesized by conventional solid-state reaction method with different concentrations of x (¼ 0:05 (BZT1), 0.10 (BZT2), 0.15 (BZT3), 0.20 (BZT4), 0.25 (BZT5), 0.30 (BZT6)). Phase confirmation of the samples was done by X-ray diffraction (XRD) technique. All the compositions are in cubic structure. XRD pattern was recorded for samples sintered at different sintering temperatures. Lattice parameters increased with addition of Zr þ4 . Doping with Zr þ4 into Barium titanate resulted in interesting changes of electrical properties (dielectric, impedance and ferroelectiricity). The strong influence of Zr doping on the phase transition characteristics of the BZT ceramics was studied from the dielectric response of the samples. Diffusivity of phase transition of the BZT ceramic samples increase with Zr þ4 concentration, indicating changes from normal to diffuse transition to relaxor phase transition behavior. Impedance spectroscopy reveals the presence of temperature-dependent grain, grain boundary effects. Polarization-Electricfield (PE) loop measurements are also done on the samples.

Dielectric and Impedance Analysis on the Electrical Response of Lead-Free Ba1−xCaxTi0.9Zr0.1O3 Ceramics at High Temperature Range

“…More conveniently seen from the dielectric loss (tan δ), the dielectric anomaly was associated with a process of relaxation [17]: loss peaks shifted toward higher temperatures with an increase in the frequency (Figure 4c). The associated physical properties of BCTZ ceramics after T C are related to relaxation and conductivity processes [17][18][19][20][21]. For ferroelectric materials, it is important to perform a complete analysis of their electrical properties to separate different electroactive contributions (grain/bulk and grain boundary) and their frequency/temperature dependence.…”

Structural, dielectric and AC conductivity studies on 0.8Ba0.2(Bi0.5K0.5)Ti1-xZrxO3 lead free ceramic system

“…Dielectric loss is higher at lower frequencies and decreases with an increase of frequency. It shows that at higher frequencies dipoles were unable to follow the applied AC field and hence, a decrease in dielectric loss at higher frequencies occurred [6][7][8]11]. Zhi et al [16] reported that dielectric constant value also depends on the density of the samples.…”

“…This is due to the substitution of large size Zr 4+ cation (0.072 nm) in place of small size Ti 4+ cation (0.0605 nm) as this substitution depresses the oriented displacement of B-site ions in the oxygen octahedra. Therefore, the interaction between B-site ions and oxygen ions in the oxygen octahedra would become weaker, resulting in the decrease of phase transition temperature [1,2,8,9,11].…”

“…Effect of Zr substitution in BaTiO 3 has been extensively studied by many authors using different methods for different applications at different experimental conditions [1][2][3][4][5][6][7][8][9][10][11]. Zr substituted BaTiO 3 ferroelectric materials have been used as multilayer ceramic capacitors (MLCC), pyroelectric sensors, piezoelectric actuators, etc.…”

On the high temperature phase transition in Ba(Zr0.20Ti0.80)O3ceramic

“…Barium zirconate titanate, Ba(Zr,Ti)O 3 (BZT) is a well-known stable lead-free ferroelectric material which finds many technological applications such as relaxor, [1][2][3][4][5] microwave, 6 high voltage, 7 high temperature, 8 actuator, 9 piezoelectric, [10][11][12] energy storage, 13 magnetoelectric. 14 Investigations have been taken up world-wide with different aims on the solid solutions of BZT with other materials like: (Ba,Ca)TiO 3 , [15][16][17][18][19] (Bi 1=2 Na 1=2 ÞTiO 3 , [20][21][22][23] 29 NiO, 30 Ni, 31 polyvinyl alcohol, 32 epoxy, 33 Portland cement, 34,35 etc.…”