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Herein, the multiferroic perovskite Er0.9La0.1Cr0.8Fe0.2O3 was synthesized using the sol–gel method, and its structure and multiferroic properties were investigated. The magnetic order of Er0.9La0.1Cr0.8Fe0.2O3 was analyzed through magnetic entropy change curves. Furthermore, a four‐sublattice molecular field model was constructed to study the spin reorientation phenomena and explain the differences between various spin redirections through magnetic order correction. This work will provide a new perspective for studying the properties of type II multiferroic materials. [ABSTRACT FROM AUTHOR]

A series of Bi 0. 8 Ba 0. 2 Fe 1 − x CoxO3 (x = 0. 0 0 , 0.05, 0.10, and 0.15) samples were synthesized using the tartaric acid modified sol–gel method. The crystal structure of the prepared samples was analyzed by XRD, and the samples co-doped with Ba and Co were all rhombohedral distorted structures with the R3c space group. With an increase in the doping amount, a reduction in lattice parameters was observed along with crystallite sizes consistently being below 62 nm. Mössbauer spectral analysis at room temperature reveals a good fit with two sextets and a doublet, all attributed to the Fe 3 + state. This suggests that the charge balance within the samples is maintained through the generation of oxygen vacancies in the system. The hysteresis loops of all samples revealed the weak ferromagnetic of the Co-doped Bi 0. 8 Ba 0. 2 FeO3 nanoparticles. With the increase in Co doping, the magnetic parameters such as saturation magnetization and coercive field significantly improved. [ABSTRACT FROM AUTHOR]

In this study, DyFe1−xCrxO3 (DFCO) was synthesized by sol-gel and underwent magnetic measurements and analysis. The experimental data were fitted and calculated by a four-sublattice molecular field model. Unlike previous studies, we found that in DyFe1−xCrxO3, the spin of the A-site rare earth ion Dy3+ also changed simultaneously with the spin reorientation of the Fe3+/Cr3+ ions. The effective spin is defined as the projection of the A site’s total spin on the B site’s spin plane, and the curve of temperature changes was obtained after fitting. This is convincing and, at the same time, provides a reference for the development of spintronic devices in the future. [ABSTRACT FROM AUTHOR]

In this paper, we irradiated K0.4Co1.3[Fe(CN)6]·nH2O with infrared light ([KCoFePBA]IIP) during the preparation process and compared them with normal preparations ([KCoFePBA]NP). XRD results show that the samples conform to the Fm-3 m space group, and the lattice constants are 10.230 Å ([KCoFePBA]NP) and 10.225 Å ([KCoFePBA]IIP), respectively. According to the results of Mössbauer spectroscopy, due to the induction of infrared light during the preparation process, part of the electrons are transferred from Co2+ to Fe3+, the paramagnetic Fe3+ (S = 1/2)-CN-Co2+ (S = 3/2) changes to the diamagnetic Fe2+ (S = 0)-CN-Co3+ (S = 0) by charge transfer. The magnetization measurement shows that the magnetization of [KCoFePBA]IIP is significantly less than that of [KCoFePBA]NP. At 300 K, the theoretical magnetic moments of [KCoFePBA]NP and [KCoFePBA]IIP are 4.60 µB and 4.37 µB, respectively. The difference in magnetism can be attributed to the charge transfer caused by infrared irradiation during the preparation process. [ABSTRACT FROM AUTHOR]

In this paper, La 1 − x CaxFeO3 (x = 0 , 0.1, 0.2, 0.3, 0.4, 0.5) perovskite samples were synthesized by sol–gel method. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Mössbauer were used for measuring. XRD measurement shows that the unit cell volume of LaFeO3 gradually decreases with increasing Ca content. The morphology of the sample was observed by TEM, and there were significant changes in volume and size of the samples with different calcium contents. Mössbauer spectrum study found that with the gradual increase of Ca content, Fe 3. 5 + and Fe 4 + were formed in the sample. The study in this paper will provide a reference for future research on the effect of different calcium contents on the electronic structure of lanthanide ferrite. [ABSTRACT FROM AUTHOR]

The synthesis of REFe0.5Cr0.5O3 (RE = La, Y) using the sol–gel method is focused and their structural differences are investigated. The results of X‐ray diffraction show that the change of ion radius at position A leads to varying degrees of octahedral distortion and spatial group structure. The scanning electron microscopy analysis reveals micron‐level particles with clear boundaries, while energy‐dispersive X‐ray spectroscopy and room temperature Mössbauer spectra indicate the presence of Fe/Cr clusters in the sample and the transitional valence of iron. Disorder in the B position leads to a saturation moment that is lower than the theoretical value. The thermomagnetic profile shows a reversal of magnetization due to the interaction between the single‐ion magnetic anisotropy and the antisymmetric Dzyaloshinskii–Moriya (DM) interaction, with a broader peak is observed due to cluster formation. The difference in negative magnetic field is due to the difference in net magnetic moment caused by different DM intensities. [ABSTRACT FROM AUTHOR]

NdFe1−xCoxO3 samples are prepared by the sol–gel method. The X‐ray diffraction (XRD) results show that these samples conform to the orthogonal perovskite structure (Pbnm), and different doping amounts can cause the patterns to shift by XRD pattern. Through the Williamson–Hall analysis, the microstrain of the lattice between different doping amounts was obtained, and the average crystal size was calculated. The element content of each sample was obtained by scanning electron microscope and energy‐dispersive X‐ray analysis. Mössbauer spectra show that different doping levels change the surrounding environment of iron, and the magnetic properties of the samples also change. [ABSTRACT FROM AUTHOR]

Thermally induced spin control is one of the main directions for future spin devices. In this study, we synthesized single-phase polycrystalline ErFe 1 − x CrxO3 and combined the magnetization curves and Mössbauer spectra to determine the macroscopic magnetism at room temperature (RT). The magnetization of the system at various temperatures is well simulated by molecular field theory. And it is found that under the Dzyaloshinskii–Moriya (DM) interaction, not only the B-site ions undergo a reorientation process, but the spins of the A-site ions also change at the same time. The effective spin is defined as the projection of Er 3 + on the Fe 3 + /Cr 3 + spin plane, and the whole reorientation process is obtained by fitting. This study will complement the actual process of ErFe 1 − x CrxO3 spin reorientation and will lay a theoretical foundation for the fabrication of future spin-controlled devices. Under the control of a certain temperature, the magnetic rare earth perovskite EFCO, in addition to the known spin reorientation of the B-site ions, also has a special spin turn of the A-site rare earth ions, that is, the value of the effective spin (the projection of the full spin on the B-site spin plane) also changes. [ABSTRACT FROM AUTHOR]

In this paper, a series of M-type hexagonal SrCoxFe12−xO19 (x=0, 0.25, 0.5) samples have been prepared by sol–gel method. X-ray diffraction (XRD) showed that the samples produced were all p63/mmc space groups of single hexagonal crystals, and the lattice parameters a, b and c did not show the expected trend with increasing x. This was related to the valence changes and lattice distortion caused by the substitution of Co2+ at the 2a and 4f2 sites. Room temperature Mössbauer spectra studies showed that when x=0, Fe3+ ions were not uniformly distributed, preferring the 4f1, 4f2 and 2a sites; when x=0.25, Co2+ ions preferentially displaced the 2a and 4f2 sites and the presence of Fe2+ was detected; when x=0.5, Co2+ ions preferentially displaced the 4f1 and 2b sites and the percentage of Fe2+ occupancy was reduced, with a greater occupancy (RA) occurring at the 12k site, indicating a preference of Fe3+ of the doped sample for this site. This work will provide an important reference for the variation of properties induced by different ion doping substitutions of the Fe sites in the hexagonal ferrite family. [ABSTRACT FROM AUTHOR]

Superhydrophobic materials hold great promise in emulsion separation, but they have inherent mechanical weakness and are ineffective to separate mixed surfactant-stabilized emulsions. Herein, we combined the adhesion ability of polyphenol-Fe 3+ bis-complexes with the high mechanical strength of carbon nanotubes (CNTs) to construct a mechanically robust and superhydrophobic coating on a collagen fiber membrane (CFM). We demonstrated that both CNTs and polyphenolic complexes competed with the surfactants adsorbed onto the emulsion droplets, serving as efficient demulsifiers to various mixed surfactant-stabilized emulsions. CFM has a 3D fibrous structure and a high limiting oxygen index, which provides high flux and flame resistance. The as-prepared superhydrophobic membrane can separate diverse anionic/nonionic and cationic/nonionic surfactant-stabilized micro- and nanoemulsions under gravity, with a separation efficiency and flux up to 99.999 % and 1695 L m -2  h -1 , respectively. The membranes also retained the emulsion separation ability after sandpaper abrasion. These features demonstrate a practical technology for emulsion separation., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An analytical method has been developed for the determination of 28 organochlorine pesticides and pyrethroid pesticides in pine nuts. The sample was extracted With acetonitrile-water (4:1, v/v) as the extraction solution by means of high-speed homogenization. The crude extract was purified by an Aluminium-N solid phase extraction column to remove most of the fat and sterols in the sample, then on-line gel permeation chromatography-gas chromatography/ mass spectrometry (GPC-GC/MS) analysis was performed. The recoveries for the most of pesticides in the sample spiked with the standards of 0.05 mg/kg were 70%-120%, and the relative standard deviations were less than 15%. The limits of detection of 28 organochlorine pesti- and pyrethroid pesticides were 0.002-0.05 mg/kg. The linear relationship and the recovery results were satisfactory. The method is rapid, accurate, highly senstive, and can be used for the simultaneous determination of pesticide residues in pine nuts.