Structural and dielectric properties of Ba0.95Bi0.05Ti1-xFexO3ceramics at x=0.0, 0.1 and 0.2 prepared by solid state method

Abstract

<jats:p>The Ba0.95Bi0.05Ti1-xFexO3 ceramics at (x=0.0, 0.1 and 0.2) were prepared by the solid-state reaction method. The effect of iron substitution on structural and dielectric properties of Ba0.95Bi0.05TiO3 ceramic was studied. These compounds are found to crystallize in only tetragonal phase for x = 0.0 and 0.1 and the mixture of tetragonal and hexagonal phases for x = 0.2. The dielectric properties of Ba0.95Bi0.05Ti1-xFexO3 ceramics at x=0.0, 0.1 and 0.2 of Fe -doping concentration. The dielectric measurements as a function of temperature and frequency are studied and showed two diffuse phase transition and relaxation phenomena. The evolution of dielectric permittivity as a function of the frequency of undoped Ba0.95Bi0.05TiO3 show a relaxation phenomenon for which is displaced to the higher frequencies accompanied by a decrease in dielectric constant when x increase. The Complex impedance Cole-Cole plots showed a negative temperature coefficient of resistivity (NTCR) behavior of the Ba0.95Bi0.05Ti1-xFexO3 materials and increased in grain and grain boundaries resistivity. The relaxation behavior in the test materials is found to be of non-Debye type.</jats:p>

Effect of Bi³⁺ and Fe³⁺ Ions Substitution on Electrical Response of BaTiO₃ Ceramic

“…In addition to the specifc concentration of 5 % of Bi doping, a maximum of the dielectric constant is achieved in other works [17,19]. And according to our previous published works [20][21][22], the relative dielectric permittivity εr was improved and reach a value of 37 000 in Bi substituted BTFO ceramics for x=0.60 and 0.80 of Fe content and the phase transitions present a relaxation behavior with diffuse character. In these works the structural, microstructural and dielectric properties of Fe and Bico-substituted BaTiO3 ceramic were studied.…”

“…The Bi and Fe substituted BaTiO3ceramics for x=0.00 to 1.00 of Fe contents and 0.05 of Bi content were synthesis using the conventional solid-state method as it is reported in our previous works [20][21][22]. The samples were prepared by the following chemical equation:…”

Investigation of relaxor and diffuse dielectric phase transitions of Ba1-XBixTi0.8Fe0·2O3 materials

“…Meanwhile, Fe-doped BaTiO 3 ceramics show some inconveniences that limit its application which are the low dielectric permittivity values and high dielectric phase transitions, which were confirmed by several works [ [35] , [36] , [37] ] On the other hand, the co-substitution of BaTiO 3 with Fe 3+ and Bi 3+ ceramics opens new possibilities to improve physical properties which could be compared with BFO-BT composites properties. The effect of BT co-substituted ceramics with Bi 3+ and Fe 3+ on structural, dielectric and ferroelectric properties were recently investigated in our works [ 38 , 39 ]. And it has been reported that the substitution of Fe 3+ ions into the Ti 4+ sites enhance the dielectric permittivity of Ba 0·95 Bi 0·05 TiO 3 ceramic and tree phase transitions were reported assigned to Rhombohedral-Orthorhombic at T R-O = 150 °C, and Orthorhombic-Tetragonal at T O-T = 350 °C then Tetragonal- Cubic at T m > 350 °C.…”