Magnetically Tunable Resistive Switching in Mn-Doped SnO ₂ Thin Films

Memristive devices based on transition metal oxides have attracted significant attention for next-generation nonvolatile memory and neuromorphic computing applications. In this work, Mn-doped SnO2 thin films were deposited on Si(111) substrates using the ultrasonic spray pyrolysis (USP) technique, and their structural, optical, and memristive properties were systematically investigated. X-ray diffraction analysis confirmed the formation of a tetragonal rutile SnO2 phase without secondary phases, while the crystallite size decreased from 34 to 23 nm upon Mn doping, indicating lattice distortion. Optical studies revealed a concentration-dependent reduction in the band gap from 3.67 to 3.24 eV with increasing Mn content, attributed to impurity states and defect levels introduced by Mn incorporation. Electrical measurements of Ag/SnO2:Mn/Si structures demonstrated stable bipolar resistive switching with well-defined high- and low-resistance states, governed by the formation and rupture of conductive filaments associated with oxygen vacancy migration. Furthermore, the application of an external magnetic field led to a decrease in the hysteresis area of the current–voltage characteristics, suggesting suppression of filament formation due to magnetic-field-induced modulation of charge transport. These results indicate that Mn-doped SnO2 thin films exhibit magnetically tunable memristive behavior, highlighting their potential for multifunctional memory and spintronic device applications.