Ferromagnetism in Fe-doped CdSe nanorods prepared by solvothermal route

The present work deals with the role played by structural defects and doping concentration on the observed ferromagnetic behavior in pure and Fe-doped CdSe nanorods. X-ray diffraction and Raman analyses reveal the formation of wurtzite phase hexagonal structure of the pure and Fe-doped CdSe nanorods, without any additional parasitic secondary phases. Selected area electron diffraction, transmission electron microscopy and high-resolution transmission electron microscopy results show the single crystalline nature of the synthesized nanorods, possessing diameter and length around 8–15 and 100–140 nm, respectively. Energy dispersive spectroscopy and UV–visible spectra indicate the incorporation of Fe in host nanorods. Electron spin resonance analysis shows that the Fe ions are present in +3 oxidation state in host CdSe nanorods. The magnetization versus applied field (M–H) curves has been measured with vibrating sample magnetometer at room temperature. The increase of saturation magnetization with Fe-doping concentration has been observed which can be explained by the bound magnetic polaron (F-center exchange mechanism) at defect sites in the host CdSe nanorods.