Charge transport and ferromagnetic interactions in Ti double-doped ZnO nanorods for spin electronic applications

In this study, (Co, Ti) co-doped ZnO nanorods (NRs) were synthesized and thoroughly examined to examine their dielectric, electrical, and magnetic characteristics, for spintronic-based applications. The dielectric response was measured as a function of frequency, showing a significant decrease at higher frequencies. This behavior was attributed to ionic hopping and charge transfer conduction losses at low and intermediate frequencies, with ionic disturbances dominating at higher frequencies, highlighting the role of dopants in optimizing the material for energy storage applications. The electrical conductivity studies found a frequency-dependent rise, with higher frequencies showing a rapid rise, consistent with hopping conduction processes attributed to oxygen vacancies and defect-mediated magnetic coupling. The room-temperature magnetic measurements demonstrated that the co-doped ZnO samples behaved ferromagnetically. The (Co, Ti) co-doped ZnO (0.03) NRs displayed the highest saturation and remanent magnetization values, with Ms = 2.27 emu/g and 0.015 emu/g, along with a coercive field was 63.04 Oe respectively. At room temperature, the co-doped ZnO (0.03) NRs showed RTFM with Curie temperature (TC) ranging from 230 to 365 K. The ferromagnetic cluster formation was suggested by the blocking temperature of 189 K shown by the zero-field-cooled (ZFC) and field-cooled (FC) curves. The electrical resistivity and specific heat measurements showed semiconductor behavior with a ferromagnetic transition and stable thermal properties, respectively. This study highlights the role of Co and Ti co-doping in enhancing the dielectric, electrical, and magnetic properties of co-doped ZnO nanorods, positioning them as promising materials for spintronic and energy storage applications.