Phonon spectra and magnetic behaviors of hydrothermally synthesized Sm-doped ZnO nanorods

Herein one-dimensional Sm-doped ZnO nanostructures have been successfully fabricated by a simple hydrothermal method at a low temperature of 90 °C. The effect of Sm doping on the microstructure, photoluminescence and magnetism of ZnO nanorods is also investigated. FE-SEM images show that the average diameter of the Sm-doped ZnO nanorods is obviously smaller than that of ZnO nanorods. Photoluminescence spectrum of Sm-doped ZnO nanorods shows a slightly red-shifted decrease of UV emission and an enhancement of photoluminescence performance of visible emission. Raman spectrum of Sm-doped ZnO nanorods reveals that the peak intensity corresponding to the E₂ high mode decreases significantly compared with that of the pure ZnO nanorods, indicating the restraint of crystallization. Room temperature ferromagnetism is observed from magnetization curves of both ZnO and Sm-doped ZnO nanorods. The increase of the saturation magnetization induced by the Sm doping in the ZnO nanorods reveals an association with the increase of oxygen vacancies and oxygen interstitials.