Enhanced Polarization Loss toward Lanthanum–Samarium Doping-Encoded Defect Genes of Ferrite for Optimizing Microwave Absorption

Doping is an effective strategy to modulate the dielectric behaviors of microwave absorption (MA) materials, for which the complex permittivity can be manipulated by encoding defect genes in the contracted crystal, while it is seldom illustrated in the magnetic ferrite crystal. Herein, the impact of defect genes on enhancing dielectric polarization in contracted Ba1–2xLaxSmxFe12O19 (LaSm-x) crystals has been investigated by lanthanum–samarium codoping BaFe12O19. It can be found that the MA character can be expressed via dielectric polarization instructed by defect genes, and their encoded amount can be guided through doping of various contents. Profiting from these enhanced point defects, enriched oxygen vacancies, and improved vacancies on the grain boundary, the intensified defect-induced polarization causes the highest dielectric loss angular tangent above 0.5 at most testing bands in LaSm-4 (the largest shrinkage factor of 4.57%). Accordingly, LaSm-4 is awarded for its optimized MA performance, embracing a minimum reflection loss of −62.8 dB and an effective absorption bandwidth of 5.64 GHz at 2.1 mm (12.05–17.69 GHz). This work clarifies the instructive impact of defect genes encoded in ferrites on enhancing polarization loss, providing a promising strategy to strengthen dielectric loss ability in other magnetic materials.