Magnetization and Raman scattering studies of (Co,Mn) codoped ZnO nanoparticles

Abstract

Single-phase (Co,Mn) codoped ZnO nanoparticles were synthesized by an autocombustion method. Hysteresis loop was observed at 300 K for the sample Zn0.98Co0.01Mn0.01O with a low coercivity (40±5 Oe). Temperature dependence of magnetization rules out the possibility of superparamagnetism or spin-glass behavior. Raman scattering studies manifested that there might exist a defect annihilation arising from the (Co,Mn) codoped into ZnO host lattice. As the ferromagnetism of diluted magnetic semiconductors is closely related to the dopant-defect hybridization, the ferromagnetic ordering was significantly enhanced in the sample Zn0.98Co0.01Mn0.01O by the (Co,Mn) codoping, in comparison to the Zn0.99Co0.01O and Zn0.99Mn0.01O fabricated by the same method.