Abstract
Due to its theoretically anticipated and practically observed above-room-temperature ferromagnetism and lengthy spin-coherence time, TiO2 has long been regarded as a viable candidate material for diluted magnetic semiconductors. Therefore, pure and (Sr, Co) co-doped TiO2 nanostructures of different compositions were synthesized via a simple hydrothermal method. X-ray diffraction analysis confirmed the formation of a high anatase phase with grain sizes ranging between 26 and 33 nm. The functional groups of these nanoparticles were observed through Fourier transform infrared spectroscopy analysis. Furthermore, Raman spectroscopy endorsed the single phase of the prepared nanostructures. UV-Vis spectroscopy was applied to study the behavior of absorption, which indicated an increase in band gap from 3.30 eV (pure TiO2) to 3.34 eV (5% co-doped TiO2). In addition, Ti3+ centers affiliated with oxygen vacancies have been described by electron spin resonance spectroscopy. Our findings provide comprehensive insight to tailor structural and optical properties of TiO2 nanostructure by Sr and Co co-doping. The (Sr, Co) co-doped TiO2 samples show ferromagnetic behavior. The saturation and remnant magnetizations (M-s and M-r) increased from (0.821 to 2.801) memu/g and (0.23 to 0.27 memu/g) while coercivity (H-c) enhanced from 50 to 75 Oe with an increase in the concentration of dopants in the TiO2 matrix. In (Sr, Co) co-doped TiO2 specimens, oxygen vacancies have been shown to be the principal cause of room-temperature ferromagnetism. The results reveal that the improved optical and magnetic characteristics of the (Sr, Co) co-doped TiO2 are closely linked to oxygen vacancy concentrations. The (Sr, Co)-doped TiO2 nanoparticles are suitable for spin-based electronics and optoelectronics-based industrial applications.