Room-temperature ferromagnetism and optical properties of Zn1−xMnxO nanoparticles

The room-temperature ferromagnetism is observed in Zn0.98Mn0.02O nanoparticles, which is related to the host-lattice defects induced by doping Mn. The ferromagnetism in Zn0.95Mn0.05O nanoparticles can be suppressed by Mn clusters. The additional peak at 519 cm−1 is observed in Raman scattering spectra of the Zn1−xMnxO nanoparticles associated with intrinsic host-lattice defects, which become activated due to the Mn doping. The decrease in band gap and the weak intensity of absorption peak in the nanoparticles may be due to the sp–d interaction between transition metal and Zn anions.