Synthesis, Characterization and Electromagnetic Properties of SnO-coated FeNi Alloy Nanocapsules

Abstract

SnO-coated FeNi alloy nanocapsules have been synthesized by an arc-discharge method. Highresolution transmission electron microscopy and x-ray photoelectron spectroscopy analysis show that the nanocapsules have a shell/core structure with FeNi alloy nanoparticles as the core and amorphous SnO as the shell. Dielectric relaxation of SnO shell and the interfacial relaxation between SnO shell and FeNi core lead to the dual nonlinear dielectric resonance. The natural resonance in the SnOcoated FeNi nanocapsules shifts to 14.0 GHz. Reflection loss (RL) reaches -46.1 dB at 14.8 GHz for a matching thickness of 1.95 mm, while it exceeds-20 dB over the 13.6 -16.7 GHz range and it exceeds -10 dB in the whole . In addition, the optimal RL values at 5.0-7.6 GHz with the absorbing thickness of 3.4-5.0 mm just exhibit a slight fluctuation.

Chemical Structure of Fe–Ni Nanoparticles for Efficient Oxygen Evolution Reaction Electrocatalysis

“…Fe 20 Ni 80 and Fe 50 Ni 50 may be more crystalline, compared to Fe 80 Ni 20 , as a higher content of lattice planes is observed. Fe 80 Ni 20 had a d -spacing value of 0.21 ± 0.02 nm which was indexed to the lattice plane (111) of FeNi alloy by Li et al 43 Fe 50 Ni 50 had a d -spacing value of 0.20 ± 0.01 nm, and Fe 20 Ni 80 had a d -spacing value of 0.20 ± 0.02 nm, which Ding et al described to be approximately close to (110) planes of bcc FeNi alloy while Xia et al indexed the d -spacing value to (111) planes of face-centered cubic (fcc) γ-FeNi phase. 43−45 For all three samples, the nanoparticles have an apparent core–shell-like morphology (additional images presented in Figure S1 of the Supporting Information), but instead of one core being enclosed by a shell, multiple cores are surrounded by the same shell.…”

“…Fe 20 Ni 80 and Fe 50 Ni 50 may be more crystalline, compared to Fe 80 Ni 20 , as a higher content of lattice planes is observed. Fe 80 Ni 20 had a d -spacing value of 0.21 ± 0.02 nm which was indexed to the lattice plane (111) of FeNi alloy by Li et al Fe 50 Ni 50 had a d -spacing value of 0.20 ± 0.01 nm, and Fe 20 Ni 80 had a d -spacing value of 0.20 ± 0.02 nm, which Ding et al described to be approximately close to (110) planes of bcc FeNi alloy while Xia et al indexed the d -spacing value to (111) planes of face-centered cubic (fcc) γ-FeNi phase. − For all three samples, the nanoparticles have an apparent core–shell-like morphology (additional images presented in Figure S1 of the Supporting Information), but instead of one core being enclosed by a shell, multiple cores are surrounded by the same shell. From these results, we postulate that the synthesis approach causes a mixed metallic phase to form, with regions of crystallinity, where the increasing iron content causes an expansion of the lattice structure, with possible shifts in the phase present and insertion of iron into the nickel lattice likely .…”

“…20 Ni 80 and Fe 50 Ni 50 may be more crystalline, compared to Fe 80 Ni 20 , as a higher content of lattice planes is observed. Fe 80 Ni 20 had a d-spacing value of 0.21 ± 0.02 nm which was indexed to the lattice plane (111) of FeNi alloy by Li et al43 Fe 50 Ni 50 had a d-spacing value of 0.20 ± 0.01 nm, and Fe 20 Ni 80 had a d-spacing value of 0.20 ± 0.02 nm,…”