Investigations on functional properties of hydrothermally synthesized Ba1-xSrxFe12O19 (x=0.0-0.8) nanoparticles

The hexagonal Ba1-xSrxFe12O19 (x = 0.0, 0.2, 0.4, 0.6 & 0.8) (BSFO) nanoparticles were synthesized by hydrothermal method at low operating temperature of 150 degrees C/8 h. Latter, the diffraction peaks confirmed the hexagonal structure. The spheres (x = 0.0, 0.2 & 0.6), flat plates (x = 0.4) and rectangular fibers (x = 0.8) like grains were noticed in the microstructure. The transmission electron microscope (TEM) studies revealed the particle diameter (D-P) changing from similar to 7-29 nm for all samples. Furthermore, the narrow optical band gap energies (E-g) were noted to be similar to 2 eV which may be suitable for optoelectronic and photocatalytic applications. Moreover, the temperature dependent ferroelectric behavior of BSFO was examined using polarization versus applied electric field (P-E) loops. The space charge polarization was observed at low frequencies of dielectric constant (epsilon'), dielectric loss (epsilon ''), ac-conductivity (alpha(ac)), dielectric modulus (M' & M ''), and impedance (Z' & Z '') plots of BSFO. The Arrhenius plots (ln sigma versus 10(3)/T) were dawn to find the activation energies (E-a & E-b). Moreover, the Cole-Cole plots were also drawn as a function of temperature from 313 to 473 K in order to investigate the conduction mechanism through grain/grain boundaries.