Effect of La-Cu co-substitution on structural, microstructural and magnetic properties of M-type strontium hexaferrite (Sr1−xLaxFe12−xCuxO19)

[Display omitted] •Sr1−xLaxFe12−xCuxO19 (x = 0.0, 0.05, 0.1, 0.15 and 0.2) nanohexaferrite systems.•XRD picture showed the single-phase pure magnetoplumbite hexagonal structure with a space group of P63/mmc.•The morphology shown by FESEM supported the other results obtained.•The room temperature VSM study shows their higher magnetization values due to their grain sizes.•The coercivity field shows an increase in magnitude from 3843.88 Oe to 7810.55 Oe. The copper substituted various stochiometric compositional nano hexagonal ferrites of Sr1−xLaxFe12−xCuxO19 (x = 0.0, 0.05, 0.1, 0.15 and 0.2) are synthesized successfully via sol–gel auto-combustion method and subsequently sintered the samples at a temperature of 1200 °C/2 hrs. We observed the effect of La-Cu substitution on the structural and magnetic properties of hexagonal strontium ferrites. X-ray diffraction pattern reveals monophasic magnetoplumbite hexagonal structure with a space group of P63/mmc, chemically pure, nanocrystalline, and magnetically ordered particles with magnetic properties. The unit cell parameter (a = b) unit cell parameter is found to decrease 5.896 Å to 5.857 Å whereas, crystallite sizes were observed to decrease from 36.28 nm to 20.07 nm with the increase in doping. FTIR spectra reveals the presence of octahedral and tetrahedral vibrational modes near 400 cm−1 and 600 cm−1 respectively which confirms the formation of hexaferrite phase. Saturation magnetization (Ms) increased from 62.37 emu/g to 67.27 emu/g with the increase in doping.