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Monodisperse cobalt chromium ferrite (FeCoCrO4) nanoparticles have been synthesised using the trimetallic pivalate cluster [CrCoFeO(O2CtBu)6(HO2CtBu)3]. The precursor was thermolysed in oleylamine and oleic acid, with diphenyl ether as the solvent at 260 °C. The effect of time and the concentration of the precursor on the stoichiometry of the phase formed and/or the morphology of the nanoparticles was studied. The reaction time was investigated by withdrawing aliquots at different times. No products were formed after 5 minutes and aliquots withdrawn at reaction times of less than 1 hour contain traces of iron oxide (Fe2O3); only cubic cobalt chromium ferrite (FeCoCrO4) was obtained after one hour. Transmission Electron Microscopy (TEM) showed that more monodisperse spherical ferrite nanoparticles (4.0 ± 0.4 nm) were obtained at higher precursor concentrations. Magnetic measurements revealed that all the ferrite particles are superparamagnetic at room temperature but showed large hysteresis at low temperature. The nanoparticles were characterised by Powder X-Ray Diffraction (p-XRD) and Transmission Electron Microscopy (TEM). A Superconducting Quantum Interference Device (SQUID) was used to analyse the magnetic properties of the nanoparticles. [ABSTRACT FROM AUTHOR]

Monodisperse cobalt chromium ferrite (FeCoCrO4) nanoparticles have been synthesised using the trimetallic pivalate cluster [CrCoFeO(O2CtBu)6(HO2CtBu)3]. The precursor was thermolysed in oleylamine and oleic acid, with diphenyl ether as the solvent at 260 °C. The effect of time and the concentration of the precursor on the stoichiometry of the phase formed and/or the morphology of the nanoparticles was studied. The reaction time was investigated by withdrawing aliquots at different times. No products were formed after 5 minutes and aliquots withdrawn at reaction times of less than 1 hour contain traces of iron oxide (Fe2O3); only cubic cobalt chromium ferrite (FeCoCrO4) was obtained after one hour. Transmission Electron Microscopy (TEM) showed that more monodisperse spherical ferrite nanoparticles (4.0 ± 0.4 nm) were obtained at higher precursor concentrations. Magnetic measurements revealed that all the ferrite particles are superparamagnetic at room temperature but showed large hysteresis at low temperature. The nanoparticles were characterised by Powder X-Ray Diffraction (p-XRD) and Transmission Electron Microscopy (TEM). A Superconducting Quantum Interference Device (SQUID) was used to analyse the magnetic properties of the nanoparticles. [ABSTRACT FROM AUTHOR]

Magnesium ferrite (MgFe2O4) nanofibers were synthesized by direct annealing of electrospun precursor fibers using an appropriate heat treatment process. The crystal structure, morphology and surface area of the as-synthesized MgFe2O4nanofibers were investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, respectively. The optical properties of the as-synthesized products were studied through ultraviolet-visible and photoluminescence spectroscopy. Due to its potential application in photocatalysis, the photocatalytic degradation of tetracycline (TC) was conducted, and the result indicated that MgFe2O4showed a better photocatalytic degradation ratio (1.5 times and 2 times) of TC than the others under visible-light irradiation, which may be due to the unique rod-in-tube structure, and larger specific area and the larger specific surface area could absorb more catalyst and provide more active sites. [ABSTRACT FROM AUTHOR]

An efficient and adaptable method is demonstrated for the synthesis of lithium hexacyanoferrate/conductive polymer hybrids for Li-ion battery cathodes. The hybrids were synthesized via a one-pot method, involving a redox-coupled reaction between pyrrole monomers and the Li3Fe(CN)6 precursor. The hybrids showed much better cyclability relative to reported Prussian Blue (PB) analogs. [ABSTRACT FROM AUTHOR]

Nanocondensates of rocksalt-type (R) magnesiowüstite and minor spinel-type (S) magnesioferrite with paracrystalline distribution of defect clusters were fabricated by pulsed laser ablation of MgO–Fe2O3 solid solution (9 : 1 molar ratio) under specified power densities in air and characterized by X-ray/electron diffraction and optical absorption spectroscopy. The predominant magnesiowüstite nanocondensates have well-developed {100}, {110}, {111} facets for (hkl)-specific coalescence as unity and bicrystal with exact/almost {110} 70.5° twist boundary, {111} twin boundary, (11̅1̅)/(001) heterointerface, and (100)R/(310)S interphase interface constrained by [01̅1]R//[001]S. The magnesiowüstite nanocondensates have a minimum band gap of ca. 3 eV for potential opto-electronic catalytic applications and a significant internal compressive stress of ca. 2.5 GPa when fabricated at a relatively high power density, shedding light on its natural high-pressure occurrence. [ABSTRACT FROM AUTHOR]

The solvothermal reactions of an equimolar mixture of FeF2 and FeF3 with Htaz (1,2,4-triazole), aqueous HF and DMF (dimethylformamide) at 120 °C yielded a series of new hybrid fluoroferrates (1–5). Their structures were characterized by either single crystal or powder X-ray diffraction data analysis. Both classes of hybrid networks were observed according to the Fen+/Htaz/HF starting ratio: class I for 1 and 2 and class II for 3, 4 and 5. Four compounds, [Hdma]·(Fe2(H2O)4F6) (1), [Hdma]·(Fe2(H2O)4F6)·0.5H2O (2), Fe2F5(Htaz) (3) and [Hdma]·(Fe2F5(H2O)(Htaz)(taz)) (4), exhibit both Fe(ii) and Fe(iii) oxidation states while [Hdma]·(Fe2F5(taz)2) (5) contains only Fe(iii) cations. [Hdma]·(Fe2(H2O)4F6) (1) and [Hdma]·(Fe2(H2O)4F6)·0.5H2O (2) contain anionic inorganic chains of alternating corner-sharing Fe(ii) and Fe(iii) octahedra; they are weakly hydrogen bonded to dimethylammonium cations [Hdma]+ which are formed by the in situ hydrolysis of DMF. The structure of Fe2F5(Htaz) (3) exhibits a three dimensional inorganic network resulting from the association of HTB planes of corner sharing FeIIF4N2 and FeIIIF6 octahedra. [Hdma]·(Fe2F5(H2O)(Htaz)(taz)) (4) and [Hdma]·(Fe2F5(taz)2) (5) reveal two original two-dimensional sheets. In 4, the deprotonated and neutral amines connect trinuclear Fe3F10N6 units of corner-sharing octahedra and mononuclear FeN4(H2O)2 octahedra. Infinite Fe2F5(taz)2 layers in 5 are built up from dinuclear species connected by deprotonated amines along two perpendicular directions. The thermal behavior and Mössbauer spectrometry results are detailed for the first tridimensional mixed valence hybrid fluoroferrate (3). [ABSTRACT FROM AUTHOR]

The reaction of trans-[Fe(R-bpb)(CN)2]− (R-bpb2− = R-substituted-1,2-bis(pyridine-2-carboxamido)benzenate) with trans-Mn(III) Schiff base complexes [Mn(5-X-saltn)]ClO4 (5-X-saltn2− = N,N′-propanolbis(5-X-substituted-salcylideneiminato) dianion) gave rise to cyanide-bridged neutral binuclear [MnFe] compounds [Mn(saltn)(MeOH)][Fe(bpb)(CN)2]·3H2O (1), [Mn(saltn)(H2O)Fe(bpmb)(CN)2]·H2O (2), [Mn(saltn)(MeOH)Fe(bpClb)(CN)2]·2H2O (3), and ionic [Mn2Fe]+-[Fe]− complexes [Mn2(5-Br-saltn)2(H2O)(EtOH)Fe(bpb)(CN)2][Fe(bpb)(CN)2]·6H2O (4) and [Mn2(5-Cl-saltn)2(CH3OH)(EtOH)Fe(bpb)(CN)2][Fe(bpb)(CN)2]·5H2O·MeCN (5). Four binuclear units of complexes 1–3 assemble in a head-to-tail way viahydrogen bonding giving rise to a metallo-supramolecular [MnFe]4 square, while two [Mn2Fe]+-[Fe]− units of complexes 4–5 form a metallo-supramolecular macrocyclic structure. Magnetic studies reveal that complexes 1–3 and 5 exhibit intermetallic ferromagnetic coupling, while complex 4 displays antiferromagnetic interaction between low-spin Fe(III) and high-spin Mn(III) through the cyanide bridges. Complexes 1, 4 and 5 display frequency dependent of current-alternating (ac) magnetic susceptibility, typical of the presence of slow magnetization relaxation. Because of the existence of intermolecular magnetic interaction, complex 4 shows an exchange-biased single-molecule magnet (SMM) behavior below 0.5 K. [ABSTRACT FROM AUTHOR]