Structural and magnetic studies on transition metal (Mn, Co) doped ZnO nanoparticles

We report on the structural and magnetic properties of the nanocrystalline samples of Zn1−x(TM)xO (TM=Mn, Co and x=0.02, 0.05, 0.10) synthesized by chemical vapor deposition (CVD) method using different carrier gases i.e., Argon (Ar), Oxygen (O2) and Nitrogen (N2). X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies reveal wurtzite structure of pure ZnO in all the samples and particle sizes in the range of 15–40 nm. No evidence of any secondary phases having room temperature ferromagnetic behavior has been observed through XRD and TEM studies. Magnetic measurements reveal presence of mixed magnetic phases in the samples, which may be the reason for the low saturation magnetization in the nanoparticles.

▸ Full study of magnetic data revealed the choice of carrier gas is main in defining the magnetic property of nanoparticles. ▸ Samples possess mixed magnetic phases (PM+AFM+FM) and their concentration depends on choice of carrier gas. ▸ FM fraction is found to increase in the samples synthesized using N2 synthesized samples in comparison to the O2 synthesized samples.