Boosting of Magnetic, Ferroelectric, Energy Storage Efficiency, and Piezoelectric Properties of Zn Intercalated SrBi4Ti4O15-Based Ceramics

Abstract

An appropriate amount of Zn-ions are incorporated into the high Curie temperature bismuth layer-structure ferroelectric material to fabricate Sr0.2Na0.4Pr0.4Bi4Ti4O15:xwt%ZnO; (SNPBT:xZn), with x = 0, 0.10, 0.15, and 0.20 ceramic series to investigate the magnetic, ferroelectric, and energy storage efficiency and piezoelectric properties. Pure SNPBT and SNPBT:xZn ceramics have maintained their structure even after the intercalation of Zn-ions at the lattice sites of SNPBT. The addition of ZnO in SNPBT has improved the multifunctional properties of the material at x = 0.15. At room temperature, SNPBT:0.15Zn has shown a high relative density of 96%, exhibited weak ferromagnetic behavior along with a low saturation magnetization (Ms) of 0.028 emu/g with a low coercive field of 306 Oe, a high remnant polarization (Pr) of 9.04 µC/cm2, a recoverable energy density (Wrec) of ~0.5 J/cm3, an energy conversion efficiency (η) of ~41%, a high piezoelectric co-efficient (d33) of 21 pC/N, and an impedance of 1.98 × 107 Ω, which are much improved as compared to pure SBT or pure SNPBT ceramics. Dielectric Constant (ɛr) versus temperature plots present the sharp peak for SNPBT:0.15Zn ceramic at a Curie temperature (TC) ~ 605 °C, confirming the strong ferroelectric nature of the ceramic. Moreover, SNPBT:0.15Zn ceramic has shown strong, piezoelectric, thermally stable behavior, which remains at 76% (16 pC/N) of its initial value even after annealing at 500 °C. The achieved results clearly indicate that SNPBT:0.15Zn ceramic is a promising candidate for future wide-temperature pulse power applications and high-temperature piezoelectric devices.

Influence of Mn Ions’ Insertion in Pseudo-Tetragonal Phased CaBi4Ti4O15-Based Ceramics for Highly Efficient Energy Storage Devices and High-Temperature Piezoelectric Applications

“…Moreover, during the high-temperature sintering process of the ceramics, the highly voltaic nature of Bi was unavoidable, which resulted in the appearance of vacancies. Hence, for a charge-neutrality situation, oxygen ions started to evaporate as well, and these vacancies can be overcome by the intercalation of Mn ions to reduce the mobility defect and increment of ferroelectric properties [ 38 ]. Afterwards, for CBTNF:0.20Mn, the value of P S ~14.7 µC/cm 2 started to decrease ( Figure 5 b).…”

“…This phenomenon is called back-switching at the diffusion temperature. The addition of Mn ions due to its multi-valence nature is capable of occupying the unbound misfits, which results in the development of electronic-charge dispersal at the grain boundaries, which reduce back-switching occurrence even at high-temperature annealing [ 38 ]. Herein, it can be observed that for CBTNF:0.20Mn ceramic, the d 33 value decreased to 25.2 pC/N (at room temperature) as the solubility limit of the Mn ions at vacant A and B sites in the CBTNF counterpart attained its maximum limit (percolation threshold).…”