Display omitted •SrBixLaxYxFe12−3xO19 (0.0≤x≤0.33) hexaferrites have been prepared by sol-gel autocombustion.•XRD patterns show that SrBixLaxYxFe12−3xO19 (0.0≤x≤0.33) hexaferrites exhibit hexagonal structure.•The intrinsic coercivity (Hci) above 15000Oe reveals that all samples are magnetically hard materials. SrBixLaxYxFe12−3xO19 (0.0≤x≤0.33) hexaferrites were produced via sol-gel auto combustion. XRD patterns show that all the samples are single-phase M-type strontium hexaferrite (SrM). The magnetic hysteresis (σ-H) loops revealed the ferromagnetic nature of nanoparticles (NPs). The coercive field decreases from 4740Oe to 2720Oe with increasing ion content. In particular, SrBixLaxYxFe12−3xO19 NPs with x=0.0, 0.1, 0.2 have suitable magnetic characteristics (σs=62.03–64.72emu/g and Hc=3105–4740Oe) for magnetic recording. The intrinsic coercivity (Hci) above 15000Oe reveals that all samples are magnetically hard materials. Tauc plots were used to specify the direct optical energy band gap (Eg) of NPs. The Eg values are between 1.76eV and 1.85eV. 57Fe Mössbauer spectroscopy data, the variation in line width, isomer shift, quadrupole splitting, relative area and hyperfine magnetic field values on Bi3+ La3+ and Y3+ substitutions have been determined.