Tungsten (W)-substituted SBT ceramics [SrBi2(Ta_(1-x)W_x)2O9 ; 0.0 ≤ x ≤ 0.20] were synthesized by solid state reaction method using different sintering temperatures (1100 °C, 1150 °C, 1200 °C and 1250 °C). W substitution is found to significantly affect the electrical properties of SBT, including dielectric permittivity, Curie temperature, and ferroelectricity. Dielectric constant (ε_r) and the Curie temperature (T_c) increase with increasing W content. The dielectric loss reduces significantly with increase in W concentration. The maximum T_c of ~ 390 °C is observed in the sample with x = 0.20 as compared to ~ 320 °C for the pure sample when sintered at 1200 °C. The peak e increases from ~ 270 in the sample with x = 0.0 to - 700 for the composition with x = 0.20, when sintered at 1200 °C. All the tungsten-substituted ceramics have higher 2P_r than that in the pristine sample. The maximum 2P_r (-25 uC/cm2) is obtained in composition with x = 0.05 sintered at 1200 °C. These effects have been interpreted based on the model of the recovery of oxygen vacancies upon W substitution. Such compositions with low loss and high P_r values should be excellent materials for highly stable ferroelectric memory devices.
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