Synthesis, structural and morphological characteristics, magnetic and optical properties of Co doped ZnO nanoparticles

Effect of Fe-doping on the structural, optical and magnetic properties of ZnO nanostructures synthesised by co-precipitation method

“…The band at 2931cm -1 indicated the presence of C-H stretching vibration [26]. Similar results are also reported by Mesaros et al and Singh et al [25,27]. The bands with lower intensity absorbed at around 1385 cm -1 are attributed to residual NO 3 -ions, which were not properly removed during washing, as reported by Singh et al [27].…”

“…6. The broad band located around 3440 cm -1 is due to O-H stretching vibration of adsorbed water molecules, while the band located about 1625 cm -1 is due to O-H bending vibration of the same atmospheric water [25]. The characteristic band at 2360 cm -1 is due to O = C = O stretching vibrations of residual CO 2 that is adsorbed on particles surface.…”

Enhancing the magnetic and antibacterial properties of ZnO nanopowders through Mn+Co doping

“…The characteristic bands in the range of 400-600 cm À 1 are attributed to Zn-O stretching modes [30]. Unlike in the case of undoped samples, the doped ZnO nanopowders exhibit peaks at around 630 cm À 1 which may be due to the overlapping of Mn-O and Co-O stretching modes [31,32]. This result is an indication of the substitutional incorporation of Mn 2 þ and Co 2 þ ions into the Zn 2 þ sites of the ZnO lattice.…”

Identifying the sources of ferromagnetism in sol-gel synthesized Zn1−xCoxO (0≤x≤0.10) nanoparticles

“…The spectra are composed of a dominant sharp peak centered at around 1526 G (g x = g y = 4.6) and a weaker and relatively broad signal at 3015 G (g z = 2.2). These lines are attributed to the perpendicular component (H ⊥ c) corresponding to tetrahedrally coordinated PM Co 2+ ions substituting at Zn 2+ sites in the wurzite ZnO structure and its parallel component (H || c) respectively, suggesting that the system symmetry is axially distorted [14]. The lines with a g value of ~1.96 or 20 2.004 associated to shallow donors or core-shell vacancies originating from zinc and oxygen vacancies respectively [60,61] were not detected.…”

“…Lawes et al [13] reported absence of ferromagnetism, but dominant AFM interaction, down to 2 K in bulk Zn 1-x Co x O with 0.02 ≤ x ≤ 0.15. Mesaros et al [14] prepared Zn 1-x Co x O (x = 0.05, 0.10, and 0.15) nanoparticles using a wetchemical synthesis route, and a FM behavior was revealed for the samples, however a possible origin for this magnetic interaction was not provided. Fu et al [15] prepared Co doped ZnO nanomaterials by using a hydrothermal method and suggested that the observed ferromagnetism originates probably from the Co 3+ enrichment and the coexistence of Co 2+ /Co 3+ on the particle surface, which may lead to the superexchange or a doubleexchange mechanism between those ions.…”