Correlation Between Structure and Ferromagnetism in Cobalt-Doped CdSe Nanorods

The present study deals with the investigation on structural and magnetic properties of pure and Co-doped CdSe nanorods synthesized by solvothermal route. The effects of Co-doping on structural, optical, and magnetic properties of nanorods have been explored using X-ray diffraction (XRD), transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Raman spectroscopy, energy dispersive spectroscopy (EDS), diffuse reflectance spectroscopy, electron spin resonance (ESR), and vibrating sample magnetometer (VSM), at room temperature. TEM images show that the synthesized nanorods having length in range of 80-150 nm and diameter of 10-20 nm. No ferromagnetic resonance signal has been observed in ESR spectra, indicating the absence of exchange interactions in pure and doped nanorods. The lattice contraction, increase in band gap, and ferromagnetic behavior have been observed with Co-doping concentration up to 5 %. However, at 10 % Co-doping concentration, reverse trend in above properties has been observed. The study reveals that there is a strong correlation between structural and magnetic properties of Co-doped CdSe nanorods.