Magnetic enhancement and magnetic signal tunability of (Mn, Co) co-doped SnO2 dilute magnetic semiconductor nanoparticles

Co and Mn-Co co-doped SnO2 nanoparticles have been successfully synthesized using a simple technique called as citrate precursor assisted co-precipitation (CPACP). Structural and compositional analyses by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Energy Dispersive X-Ray Fluorescence Spectrometer (EDX), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy confirmed that Co and Mn ions were incorporated into the SnO2 host lattice without changing the inherent rutile structure. The average crystallite size of the prepared samples were estimated to be in the range of 8-12 nm. In a single Co2+-doped SnO2 sample, the magnetization was observed to increase as the Co2+ ions concentration increased. The transition metal Mn can adjust the magnetic signal of the Co2+-doped SnO2 sample, which is subject to the concentration of Mn dopant. Adding a proper amount of Mn to the Co2+-doped SnO2 sample enhanced the magnetization. As the Mn2+ ions concentration increases, the magnetic properties of the (Mn, Co) co-doped SnO2 nanoparticles gradually shift from ferromagnetic behavior to superparamagnetism. However, the sample Sn0.83Mn0.12Co0.05O2 exhibits diamagnetic behavior when the concentration of Mn2+ ions is doped excessively.