Structural, optical and magnetic properties of nanocrystalline Zn0.9Co0.1O-based diluted magnetic semiconductors

Catalytic oxidation of volatile organic compounds (n-hexane, benzene, toluene, o-xylene) promoted by cobalt catalysts supported on γ-Al2O3-CeO2

“…The presence of the Ce3d 5/2 peak at 881.3eV for Co 10 /γ-Al 2 O 3 -CeO 2 and at 887.6 and 904.0eV for Co 20 /γ-Al 2 O 3 -CeO 2 characterize the presence of Ce +3 and Ce +4 in both catalysts (Beche et al, 2008;Beche et al, 2012). The Co2p 3/2 peak at 779.0eV for Co 10 /γ-Al 2 O 3 -CeO 2 and 785.6eV for Co 20 /γ-Al 2 O 3 -CeO 2 characterize the presence of Co 2+ (Lakshmi et al, 2009;Salim and Khawaja, 1992) The surface composition of cobalt is 2.81% for Co 20 /γ-Al 2 O 3 -CeO 2 and 1.35% for Co 10 /γ-Al 2 O 3 -CeO 2 , as expected due to the higher metal content of this catalyst. Table 2 also gives the Co/Ce ratio at the catalyst surfaces and the highest ratio can be observed for Co 20 /γ-Al 2 O 3 -CeO 2 , indicating cobalt enrichment at the surface in the case of this sample.…”

Comparative study of room temperature ferromagnetism in Cu, Co codoped ZnO film enhanced by hybridization

“…Its electrical and optical properties can be modified by doping with either cationic or anionic into the ZnO lattice [2][3][4]. Recently, the transition metal doped ZnO [5][6][7][8][9] thin films have aroused a lot of interest due to their importance in the basic science and technological applications. The transition metal doped ZnO is one of the most promising diluted magnetic semiconductor (DMS) candidate as it is predicted to be ferromagnetic above room temperature [10][11][12].…”

Hydrothermal synthesis of Co-doped ZnO flakes with room temperature ferromagnetism

“…However, experimental observations of magnetism of the Co-doped ZnO synthesized by different methods have been controversial for both thin films and bulk samples. A number of groups observed no ferromagnetism in Zn 1−x Co x O [4][5][6], while Kalyana Lakshmi et al [7] and Maensiri et al [8] reported ferromagnetism in Co-doped ZnO powders. Kittilstved et al [9] and Rubi et al [10] demonstrated that ferromagnetism of n-type Zn 1−x Co x O thin films and powders could be switched on or off by chemical manipulation using nitrogen or oxygen, respectively.…”