Description
In a couple of previous years, a new generation of advanced SF-NPs/CNTs hybrids with tailored magnetic properties and simultaneously retaining properties of individual components emphasizing the synergic effect began being investigated by our group [1-4]. Herein, the comparison between NZFO/f-MWCNTs composites based on Ni0.5Zn0.5Fe2O4 (NFZO) nanoparticles with 2, 5 and 25 wt.% and functionalized multi-walled carbon nanotubes (f-MWCNTs) synthesized via ex-situ method is shown. The structural and microstructural analysis confirms the efficiency of the synthesis process. The estimated crystallite size just slightly varies with the NZFO content. However, the presence of single particles, clusters and aggregates on the surface of the nanotubes is proven by Scanning-Transmission (S/TEM) electron microscopy in all analyzed composites. The dominant role of the f-MWCNTs building blocks was exposed by electronic structure analysis shown by XPS and XAS in all studied hybrids as designed. The slight redistribution of iron cations is noted in XPS, XAS, and ResPES studies. The redistribution of iron cations over tetrahedral and octahedral sites versus NZFO content is proved by studying Fe2p spectra. The magnetic properties analysis revealed the cluster-glass magnetic state of NZFO particles. The core-shell-like structure with a magnetic core and disordered layer is evidenced. The influence of Fe-based carbon matrix residues in all studied hybrids was detected.
References:
[1] A. Bajorek, C. Berger, M. Dulski, et al., J. Phys. Chem. Solids 129 (2019) 1-21
[2] A. Bajorek, B. Szostak, M. Dulski, J.M. Greneche, et al., Materials 15(3) (2022) 977
[3] A. Bajorek, B. Liszka, B. Szostak, M. Pawlyta, J. Magn. Magn. Mater. 503 (2020) 166634
[4] A. Bajorek, B. Szostak, M. Dulski, J.M. Greneche, et al., J. Magn. Magn. Mater. 585 (2023) 171150
