Loading…
Synthesis of phase-pure superparamagnetic nanoparticles of ZnFe2O4 via thermal decomposition of zinc-iron layered double hydroxysulphate
Superparamagnetic nanoparticles of zinc ferrite ZnFe2O4 were obtained by air heat treatment of iron and zinc sulfated layered double hydroxide (SLDH) Zn2Fe4(OH)12SO4·8H2O at 600°С for 1 h. The initial sulfated hydroxide was obtained on a silicon substrate as a result of 30 cycles of successive ionic...
Saved in:
Published in: | Journal of alloys and compounds 2020-01, Vol.813, p.152179, Article 152179 |
---|---|
Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | Superparamagnetic nanoparticles of zinc ferrite ZnFe2O4 were obtained by air heat treatment of iron and zinc sulfated layered double hydroxide (SLDH) Zn2Fe4(OH)12SO4·8H2O at 600°С for 1 h. The initial sulfated hydroxide was obtained on a silicon substrate as a result of 30 cycles of successive ionic layer deposition from 0.01 M solutions of the Mohr salt (NH4)2Fe(SO4)2 and zinc ammonia complex [Zn(NH3)4](NO3)2. Iron and zinc SLDH nanocrystals have the nanosheets morphology with an average thickness of 3–7 nm and a diameter of about 17 nm which are oriented perpendicular to the silicon substrate plane. Physico-chemical processes which occur during thermal treatment (25–600°С) of iron and zinc sulfated layered double hydroxide and lead to the formation of zinc ferrite at 550°С are investigated by simultaneous thermal analysis. It was found that ZnFe2O4 nanocrystals with an average size of about 30 nm and isometric morphology, which partially preserve the morphological motifs of the original SLDH nanosheets, were formed as a result of the thermal treatment of sulfated hydroxide. The obtained ZnFe2O4 nanocrystals are chemically and phase-pure, have lattice parameters a = b = c = 8.4394 Å and behave like superparamagnetic nanoparticles: they are characterized by the magnetization of 1.85 (298 K) and 12.79 (77 K) emu/g with 18 kOe applied field, and the effective magnetic moment is μeff = 24.3 μB per formula unit. This phase-pure superparamagnetic ZnFe2O4 nanoparticles can be potentially used as the basis for magnetic fluids, gas sensors, drugs for hyperthermia and magnetic resonance imaging diagnostics.
Zinc-iron hydrosulfate (Zn2Fe4(OH)12SO4) nanocrystals with nanosheet morphology were synthesized via successive ionic layer deposition, and heat treatment in the air was used to obtain chemically and phase-pure superparamagnetic zinc ferrite (ZnFe2O4) nanoparticles with partial preservation of morphology. [Display omitted]
•2D nanocrystals of Zn2Fe4(OH)12SO4 were synthesized via successive ionic layer deposition from reaction solutions.•Heat treatment of Zn2Fe4(OH)12SO4 nanocrystals were used to obtain a chemical and phase-pure zinc ferrite ZnFe2O4 nanosheets.•It was shown that ZnFe2O4 nanosheets with spinel structure exhibit superparamagnetic behavior in a wide temperature range. |
---|---|
ISSN: | 0925-8388 1873-4669 |
DOI: | 10.1016/j.jallcom.2019.152179 |