Growth mechanism and magnon excitation in NiO nanowalls

Abstract

The nanosized effects of short-range multimagnon excitation behavior and short-circuit diffusion in NiO nanowalls synthesized using the Ni grid thermal treatment method were observed. The energy dispersive spectroscopy mapping technique was used to characterize the growth mechanism, and confocal Raman scattering was used to probe the antiferromagnetic exchange energy J2 between next-nearest-neighboring Ni ions in NiO nanowalls at various growth temperatures below the Neel temperature. This study shows that short spin correlation leads to an exponential dependence of the growth temperatures and the existence of nickel vacancies during the magnon excitation. Four-magnon configurations were determined from the scattering factor, revealing a lowest state and monotonic change with the growth temperature.PACS: 75.47.Lx; 61.82.Rx; 75.50.Tt; 74.25.nd; 72.10.Di

Role of cobalt cations in short range antiferromagnetic Co3O4 nanoparticles: a thermal treatment approach to affecting phonon and magnetic properties

“…The clustering makes an evaluation of the size distribution possible. A similar behavior of nanoparticle agglomeration has also been reported from NiO 21 , ZnO 22 nanoparticles, and NiO nanowalls 23 . However, the samples annealed at 800 °C (Fig.…”

“…The value of σ is below 0.3 nm for nanoparticles annealed at 450, 600, and 700 °C indicating the distributions of nanoparticles is confined within a narrow range 24 , whereas the distribution of nanoparticles annealed at 800 °C is confined within the intermediate range 25 . Energy-dispersive spectroscopy (EDS) technique is used to detect the chemical purity and estimate the atomic percentage in a given sample 23,24 . The EDS spectra of various annealing temperatures plotted in Fig.…”

“…However, the grain size of Co 3 O 4 nanoparticles annealed at T A  = 800 °C, 85 ± 6 nm obtained from x-ray diffraction differs significantly from the result of SEM (<d> = 165 ± 23 nm). The discrepancy of obtained particle size is due to the agglomeration behavior of nanoparticles at higher annealing temperatures, which resulted in the formation of multiple domains within each nanoparticle 21–23 . The corresponding particle size of the Co 3 O 4 nanoparticles versus the annealing temperatures are shown in Fig.…”

X-ray diffraction line profile analysis of nanostructured nickel oxide: Shape factor and convolution of crystallite size and microstrain contributions

“…[2,57]. In the case of sol-gel derived nanostructured NiO samples, lattice constant is reported to decrease from 4.190 to 4.180 Å when the crystallite size increase from 16 to 54 nm [51]. Peck and Langell had reported a decrease in lattice constant of 0.12% and 0.16% respectively for NiO samples with crystallite sizes 25 and 5 nm [57].…”

“…The empirical dependence of average crystallite size and microstrain on annealing temperature is shown in Fig. 5 and are modeled using second order polynomial dependence [51]. The dependence of crystallite size on annealing temperature for the samples can be approximated by a second order polynomial, t ¼ À16.16 þ9.16 Â 10 À 2 T-5.63 Â 10 -5 T 2 where t is the average crystallite size and T is the annealing temperature in°C.…”