Gas Sensors Based on Magnetic Ferrite Materials: Influence of Rare-Earth Dopants Lanthanum and Dysprosium on Sensing Properties

Magnetic ferrites are spinel-structured transition-metal oxide-based nanoparticles that exhibit distinctive magnetic, electrical, and surface characteristics, rendering them highly promising materials for gas-sensing technologies.Rare-earth doping, particularly with lanthanum (La) and dysprosium (Dy), induces substantial alterations in crystal symmetry, electronic structure, defect chemistry, and magnetic behavior within the ferrite lattice.Such intrinsic modifications profoundly govern gas adsorption kinetics, surface reactivity, and charge-carrier transport, all of which are pivotal to achieving superior sensing performance.This review provides a rigorous and comprehensive evaluation of recent advances in La-and Dy-doped ferrite-based catalysts for gas sensors, with specific emphasis on synthesis strategies, structure-property correlations, sensing mechanisms, and key performance indicators.The analysis demonstrates that rare-earth incorporation improves sensitivity, selectivity, response stability, and thermal robustness through the generation of oxygen vacancies, modulation of grain-boundary characteristics, and enhancement of surface-active sites.The review finally concludes by outlining critical future research priorities and translational considerations for scalable, commercially viable sensor deployment.