Abstract
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•XRD data indicates upto x = 0.20 samples is a pure phase.•Sharpening of Raman peak upto x = 0.20 indicates an increase in crystallinity with substitution.•Mean grain size monotonically increases with Ca2+ substitution.•The maximum value of Ms is 72.38 emu/g in the x = 0.20 sample.•Hc varies from 5043 to 5290 Oe with Ca2+ substitution.•Maximum calcium solubility is 20 Atomic % in M-type barium hexaferrite.
The effect of Ca2+ exchange at the Ba2+ site for reporting their structural, dielectric, magnetic traits and morphological behaviour of Ba1−xCaxFe12O19 (x = 0.0–0.5) nanohexaferrites synthesized by sol–gel auto-combustion technique (SGACT), have been evaluated. XRD plots confirm the single-phase purity of the synthesized samples upto x = 0.2, but beyond that, a secondary phase (α-Fe2O3) was observed in all the synthesized samples. The FESEM studies exhibit that the average size of the grains increases from 140 nm to 276 nm as the amount of the Ca2+ ions doping increases. The increasing sharpness of the Raman peaks, as the content of the dopant ion increases (upto x = 0.2), reveals an increase in nanocrystallinity of prepared samples. The values of coercivity (Hc) lie in the range of 5043–5290 Oe. The saturation magnetization (Ms) reaches its highest value of 72.38 emu/g for x = 0.2 specimen. The dielectric constant (ε') of Ba1−xCaxFe12O19 (x = 0.0–0.5) hexaferrites was improved as a function of calcium content upto x = 0.3, whereas, it starts to decrease with frequency. Therefore, the study shows that the synthesized samples with superior values of Ms, Hc, and ε', along with low dielectric loss (tanδ) can be used for manufacturing nanomaterials which act as permanent magnets.