Significantly improved magnetic parameters of Co–La co-doped strontium hexagonal ferrites for recording applications: structural, hysteresis, and mössbauer performance metrics

M-type hexaferrite substituted with cobalt and lanthanum [SrCo1.5zLa0.5zFe12-2zO19\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\text{SrCo}}_{1.5z} {\text{La}}_{0.5z} {\text{Fe}}_{12 - 2z} {\text{O}}_{19}$$\end{document} (SCLF; 0.0 ≤z≤0.5)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\le z \le 0.5)$$\end{document}] was synthesized by auto-combustion Sol–gel methodology. XRD study indicated that prepared specimens exhibit a hexagonal magnetoplumbite phase without any secondary peak. The crystallite size decreases from 48.94 to 28.82 nm as the level of substitution increases in SrM hexaferrite. The micrographs showed an enhancement in the inter-grain connectivity of grains with substitution. Mössbauer spectra revealed the variation observed in hyperfine interactions, isomer shift, quadrupole splitting, and relative area of five sextets of Fe3+ ions. Analysis of Mössbauer depicted that the substituents tend to occupy spin-up 12k-2a sites of crystal lattice from z = 0.0 to z = 0.3, which elucidated the diminution observed in magnetization. The coercivity gradually decreased from z = 0.0 (5026.54 Oe) to z = 0.5 (862.47 Oe). The saturation magnetization initially decreased with substitution from z = 0.0 to 0.3 and then increased for z = 0.4 and 0.5 samples. The magnetic susceptibility (dM/dH) of samples derived from magnetic parameters is high for z = 0.0, 0.2, 0.3, and 0.4. Both Ms with tunable Hc and magnetic susceptibility results make them considerable materials for recording applications.