Mechanochemical Preparation and Magnetic Properties of Fe₃O₄/ZnS Nanocomposite

Abstract

Powder nanocomposite of Fe3O4/ZnS was prepared by mechanochemical synthesis in a planetary ball mill. In this reaction natural magnetite mineral Fe3O4 was used, together with zinc acetate (CH3COO)2Zn · 2H2O and sodium sulfide Na2S·9H2O, as precursors for the zinc sulfide ZnS. X-ray diffraction revealed that the sample is composed of small nanocrystalline particles, containing Fe3O4 and ZnS. The non-milled magnetite showed distinctive Verwey transition at around 120 K, this becomes suppressed after milling, as a consequence of structural disorder and presence of defects. Moreover, the reduction of saturation magnetization from 91 A m 2 /kg to 69.2 A m 2 /kg was observed, as a consequence of the milling process. The magnetization of the Fe3O4/ZnS nanocomposite was the lowest (34.5 A m 2 /kg), due to the milling and to the decreased weight fraction of the ferrimagnetic component. Nevertheless, the Fe3O4/ZnS sample demonstrates ferrimagnetic behavior as well, and its structure is less perturbed by milling, the Verwey transition, although less impressive, but is preserved.

Equimolar As4S4/Fe3O4 Nanocomposites Fabricated by Dry and Wet Mechanochemistry: Some Insights on the Magnetic–Fluorescent Functionalization of an Old Drug

“…Because of a negligible coercive force, the emerging of RT supermagnetism was declared in these NPs [68,69], due to crystallites with character sizes below the critical size of single Fe 3 O 4 domains (~54 nm) [70]. Noteworthily, the saturation magnetization of ~8 nm sized Fe 3 O 4 NPs obtained by MM in conditions similar to actual in this research was M s = 69.2 A•m 2 /kg, while in the biparticulate Fe 3 O 4 /4•ZnS nanocomposite with average sizes of Fe 3 O 4 crystallites ~22 nm, the M s value was reduced to 34.5 A•m 2 /kg [66]. Of course, the latter was also achieved due to the minor content of the ferromagnetic component in the nanocomposite prepared by dry MM, as can be expected from the reduced M s = 14.7 A•m 2 /kg observed in the triparticulate β-As 4 S 4 /4•ZnS/Fe 3 O 4 nanocomposite with smaller fraction of magnetite Fe 3 O 4 [22].…”

“…The RT magnetization in the bulk inverse-spinel-structure magnetite Fe 3 O 4 is known to achieve the maximal value, approaching M s bulk ~92 A•m 2 /kg [64][65][66]. The reduced saturation magnetization M s in this counterpart fabricated by nanostructurization without any surfactants is known to be achieved due to the finite size effect [65][66][67][68][69].…”

“…The RT magnetization in the bulk inverse-spinel-structure magnetite Fe 3 O 4 is known to achieve the maximal value, approaching M s bulk ~92 A•m 2 /kg [64][65][66]. The reduced saturation magnetization M s in this counterpart fabricated by nanostructurization without any surfactants is known to be achieved due to the finite size effect [65][66][67][68][69]. Thus, the M s value of 70 nm sized Fe 3 O 4 NPs prepared by the hydrothermal method was 68.7 A•m 2 /kg [68], while the 10 nm sized NPs prepared via sonochemical synthesis have an M s < 1.25 A•m 2 /kg [69].…”

Nanomilling-driven volumetric changes in multiparticulate As4S4-bearing nanocomposites recognized with a help of annihilating positrons

“…In biomedicinal applications, nanoarsenicals possessing improved anti-cancer functionality are often combined with NP of other nature to form multiparticulate pharmaceutical systems possessing additional advances, such as fluorescent emission due to nanostructured zinc sulfide ZnS (Fang et al 2011;Baláž et al 2016) and magnetically addressable drugdelivery functions owing to magnetite Fe 3 O 4 (Cabrera et al 2008). The groups of novel biparticulate nanocomposites such as anti-cancer-magnetic As 4 S 4 /Fe 3 O 4 (see Shpotyuk et al 2017a;Bujňáková et al 2020), anti-cancer-fluorescent As 4 S 4 /ZnS (see Bujňáková et al 2017;Shpotyuk et al 2017b) and magnetically fluorescent Fe 3 O 4 /ZnS (see Liu et al 2014;Roychowdhury et al 2014;Bujňáková et al 2016) have been emerged. The functioning principles of these multiparticulate nanocomposites occurred to be rather complicated, since they embrace diverse levels of materials organization including atomic-specific and atomic-deficient structural entities.…”

Optical, Structural and Spectroscopic Characterization of ZnS Nanocrystals Embedded in KBr Single Crystal Matrix Grown by Czochralski Method

“…Nanostructures made of ZnS are attractive in applications of electronic, optoelectronic nanodevices analysis of water pollution, environmental studies, pathological investigations [11]. They could be potentially useful for application in biological imaging due to their non-toxicity medium [12].…”