Phase Evolution, Microstructure, Electrical, and Magnetic Properties of Bi 0.5 (Na 0.68 K 0.22 Li 0.10 ) 0.5 TiO 3 Ceramics with Fe 3+ Substitution

Herein, the effect of Fe 3+ ions substitution on the phase evolution, microstructure, electrical, and magnetic properties of Bi 0.5 (Na 0.68 K 0.22 Li 0.10 ) 0.5 Ti 1− x Fe x O 3 (BNKLT‐ x Fe) ceramics with 0 ≤  x  ≤ 0.020 is investigated. The BNKLT‐ x Fe ceramics are synthesized via the solid‐state combustion method. All BNKLT‐ x Fe compositions use a calcination temperature of 750 °C for 2 h and a sintering temperature of 1025 °C for 2 h. The X‐ray diffraction (XRD) and Raman spectra illustrate coexisting rhombohedral (R) and tetragonal (T) phases in all compositions and the R phase increases with increasing Fe content. The X‐ray absorption spectroscopy (XAS) technique confirms that the local R symmetry increases from 38.8% to 67.0% with increasing x content from 0 to 0.020. The average grain size gradually increases from 0.52 to 0.84 μm when the x content increases from 0 to 0.020. At x  = 0.010, the ceramic has high ferroelectric properties ( P r  ≈ 26.8 μC cm −2 , E c  ≈ 20.4 kV cm −1 ) and the highest normalized strain ( d 33 * ) of 386 pm V −1 . In addition, the maximum value of the temperature‐dependent dielectric constant of 6136 is found at x  = 0.015. Although BNKLT‐0Fe ceramic show diamagnetic behavior, paramagnetic behavior is observed in all Fe 3+ substituted samples.