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The design and synthesis of efficient adsorbents for the recovery of precious metals from secondary resources are of great environmental and economic significance. Herein, a magnetic sulfur‐doped composite CoFe2O4@S–CoWO4 (CF@S–CoWO4) is developed through a hydrothermal synthesis method, which is used to selectively recover gold in aqueous media. Significantly, CF@S–CoWO4 exhibits the best overall performance with gold ions adsorption capacity (Qmax) and distribution coefficient (Kd) are 1049 mg g−1 and 4.4 × 106 mL g−1, respectively, which are much higher than those of other gold adsorption materials. The selectivity coefficients (K) toward other metal ions (Pd2+, Ca2+, Mg2+, Cd2+, Al3+, Li+, Ni+) are also higher, which suggests that CF@S–CoWO4 had a preferential selectivity for Au3+ in coexisting ion solutions. Moreover, the antianion interference of the composite follows the order: SO42− > PO43− > NO3− > CO32−, and it also shows very good reusability with adsorption efficiency at 81.78% after four repeated cycles. Based on characterizations and calculation, it is found that Au(III) mainly undergoes chelation and reduction reactions in the S sites in CF@S–CoWO4, which indicates the important role of S sites. Hence the CF@S–CoWO4 composite demonstrates a promising application for the recycling of gold ions from electronic wastewater. [ABSTRACT FROM AUTHOR]

The design and synthesis of efficient adsorbents for the recovery of precious metals from secondary resources are of great environmental and economic significance. Herein, a magnetic sulfur‐doped composite CoFe2O4@S–CoWO4 (CF@S–CoWO4) is developed through a hydrothermal synthesis method, which is used to selectively recover gold in aqueous media. Significantly, CF@S–CoWO4 exhibits the best overall performance with gold ions adsorption capacity (Qmax) and distribution coefficient (Kd) are 1049 mg g−1 and 4.4 × 106 mL g−1, respectively, which are much higher than those of other gold adsorption materials. The selectivity coefficients (K) toward other metal ions (Pd2+, Ca2+, Mg2+, Cd2+, Al3+, Li+, Ni+) are also higher, which suggests that CF@S–CoWO4 had a preferential selectivity for Au3+ in coexisting ion solutions. Moreover, the antianion interference of the composite follows the order: SO42− > PO43− > NO3− > CO32−, and it also shows very good reusability with adsorption efficiency at 81.78% after four repeated cycles. Based on characterizations and calculation, it is found that Au(III) mainly undergoes chelation and reduction reactions in the S sites in CF@S–CoWO4, which indicates the important role of S sites. Hence the CF@S–CoWO4 composite demonstrates a promising application for the recycling of gold ions from electronic wastewater.

In this article, the authors have explored the changes caused in structural, morphological and magnetic properties of magnesium ferrite nanoparticles (MgFe2O4 NPs) under dynamic shock wave exposure situations. Interestingly, the observed XRD and VSM results reveal that the MgFe2O4 NPs have outstanding crystallographic and magnetic phase stability against the impact of shock waves and found that the title NPs are having higher shock resistance than other potential materials such as TiO2, Co3O4 and ZnFe2O4 NPs.

Nickel oxide nanoparticles with the size of 218, 73, and 50 nm were added to Ni-P electroless coating to create NiO@Ni-P nanoparticle reinforced composite coating on a brass substrate. The nanoparticles were synthesized by the green synthesis method, using Artemisia dracunculus extract. The coatings had amorphous structure and nodular morphology. The results of Tafel and EIS tests showed that the coating containing nickel oxide nanoparticles with an average size of 73 nm, had the highest corrosion resistance. The results of the tribocorrosion test under open circuit potential condition revealed Ni-P-(73 nm)NiO coating had the highest tribocorrosion resistance. Heat treatment at 400°C caused considerable improvement in the saturation and remnant magnetization of the composite coating, the value of saturation and remnant magnetization increased from 5 and 0.1 emu/g for simple Ni-P coating to 12 and 2 emu/g for NiO@Ni-P coating respectively, and the coercive field of the samples also enhanced. [ABSTRACT FROM AUTHOR]

Bi4Ti3O12-BaTiO3 (BTO-BT) nanocomposite, a Aurivillius oxide, which is synthesised by modified solid-state route, and characterised by various techniques like FTIR, XRD, TEM, UV-DRS, Zetasizer Nano-ZS, AFM, BET, SEM-EDX and XPS for the phase identification, microstructural analysis, bandgap determination, elemental analysis and oxidation state of the material. Formation of BTO-BT nanocomposite (orthorhombic and cubic) confirmed by Le-Bail fitting analysis with the help of XRD data. The electrical measurement of the material showed the existence of semiconducting grains and insulating grain boundaries responsible for Maxwell relaxation and a high dielectric constant of value 4.75 × 103 at 368 K was observed. The Magnetic behaviour studied by SQUID indicates it to be magnetically frustrated materials. The material was found to be applicable in photocatalytic degradation of Rhodamine B under UV light through major reactive species, i.e. OH. radicals and O2.- generated during the photocatalytic reaction proved to be following the first-order kinetics. [ABSTRACT FROM AUTHOR]

Effect of Silver (Ag) doping in shaping magnetic properties of sol-gel derived TiO 2 nanoparticles (NPs) is studied using different characterisation techniques. An interconnection between the results of characterizations and the magnetic behavior of the Ag doped samples has been established. XRD patterns show an anatase to rutile phase transition in NPs at 14 at. % Ag doping. XRD peaks related to metallic Ag are found in the TiO 2 NPs containing 10 and 14 at. % Ag whereas secondary phase of Ag 2 O is noticed in all the samples. FESEM images exhibit the presence of segregated silver clusters attached to the TiO 2 nanostructures for 10 and 14 at. % Ag doping. XPS detects the presence of several cationic states in doped TiO 2 NPs. UV–Vis measurements reveal that the quantum size effect enhances the band gap at initial level of doping and afterwards it continiously decreases due to sp-d exchange interactions. M − H study shows the emergence of soft ferromagnetism (FM) in the sample doped with a critical Ag+ ion concentration of 5 at. % due to d -orbital mediated spin information transfer between two hole trapped Ag+ ion and a Ti3+ defect leading to the formation of BMP. Temperature dependent FC and ZFC magnetization measurements indicate coexistence of ferromagnetic and antiferromagnetic domains. The investigations culminate in identification of not only the optimum processing conditions for enhanced FM properties along with good physical characteristics but also the probable cause behind the origin of FM in Ag doped TiO 2 NPs. Such Ag doped TiO 2 NPs can be useful for development of futuristic spintronic and magneto-optical devices. [ABSTRACT FROM AUTHOR]

Saturation and cross‐coupling effects have a significant impact on the magnetic behaviour of a permanent magnet synchronous motor (PMSM), which cannot be analysed by the conventional linear model in the direct and the quadrature axis. This study introduces a precise two‐axis flux linkage model for PMSMs to offer a better depiction of the relationship between the flux linkages and corresponding currents. A parameter determination methodology is developed to identify the model parameters for a PMSM, and based on these works; the condition of a PMSM can be estimated. The process requires no geometrical parameter of the machine and little computational effort. Once the model parameters are determined, the torque estimation of a PMSM is simple enough to be made in real‐time in a motor drive controller. Finite‐element analysis and experimental results demonstrate the feasibility and accuracy of the improved model. It follows that the proposed non‐linear PMSM model based on current injection and bivariate function approximation can significantly enhance modelling precision of flux linkage and inductance over the entire range of current excitation in the application of PMSM drive. [ABSTRACT FROM AUTHOR]

In2O3 is multifunctional material with rich physical phenomena. In this paper, effects of Fe and Cu doping on the physical properties of In1.95-xCr0.05MxO3 (M = Fe, Cu) thin films prepared by sol-gel method followed by spin-coating technique were investigated. The films were characterised using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectrophotometer, Hall effect, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometer. Doping with Cu reduced the lattice parameter and optical transmittance of In1.95-xCr0.05MxO3 films more than that with Fe. In addition, Cu doping induced p-type conductivity in In1.95-xCr0.05MxO3 films. Optical band gap was increased from 3.76 eV for In1.95Cr0.05O3 to ~ 3.8 eV for both Cu- and Fe-doped films, which was attributed to quantum confinement behaviour. Average grain size measured using TEM was reduced from 8.2 nm for In1.95Cr0.05O3 to 6.6 and 5.6 nm for Fe and Cu doped films, respectively. Saturation magnetisation of films was reduced with Fe doping more than that with Cu doping. Magnetic behaviours of films were explained within the framework of bound magnetic polaron model. [ABSTRACT FROM AUTHOR]

Electrical steel shows a distinct non‐linear and anisotropic behaviour even for non‐oriented steel. The flux guidance in electrical machines is realised by ferromagnetic steel sheets, and therefore it is necessary to consider the anisotropy in the simulation to have reliable and accurate results. Due to the fact that the reduction of silicon steel waste in the production process of electrical machines is crucial, and to enhance the material utilisation the segmentation is employed in the construction of electrical machines. The segmentation further allows to enhance the magnetic behaviour of the machine by considering the easy magnetisation axis in the design process. Nowadays, consideration of ferromagnetic anisotropy in the simulation of electrical machines is not accurate. To cope with these inaccuracies, in this contribution, a vectorial anisotropy model based on two‐dimensional measurements is employed to the simulation of a segmented electrical machine, which is not state of the art in current machine computation. With the presented methodology, it is possible to simulate and design segmented electrical machines in an accurate fashion taking the ferromagnetic anisotropy into account. [ABSTRACT FROM AUTHOR]

Coated steel substrate by FeCo/Al 2 O 3 nanoparticle with various Co concentrations realized by a thermal spraying process, preliminary powder alloy was elaborated by mechanical alloying technique for 20 h of milling time. The aims of this work are to study the effect of thermal spraying process and mechanical alloying on chemical composition, magnetic behaviour, structure and mechanical properties of coating. After mechanical alloying, the crystallite sizes of the powder were decreased from 18 to 7 nm and the lattice strains increased from 0.36 to 0.56%. This is due to the phenomenon of diffusion of cobalt in the iron lattice and the milling effect. After thermal spraying, many different phases appeared in the coating, such as Al 2 FeO 4 , CoAl 2 O 4 , CoFe and CoFe 2 O 4 . Magnetic behaviour was influenced by this change in the chemical composition of coating. The maximum saturation magnetization was found in Fe 40 Co 20 (Al 2 O 3) 40 sprayed powder, however, the minimum coercivity was found in Fe 50 Co 10 (Al 2 O 3) 40 sprayed powder. Mechanical properties' parameters such as microhardeness and Young's modulus were enhanced by the change in chemical composition during mechanical alloying and thermal spraying process. [ABSTRACT FROM AUTHOR]

The dissolution of anhydrous iron bromide in a mixture of pyridine and acetonitrile, in the presence of an organic amine, results in the formation of an [Fe34] metal oxide molecule, structurally characterised by alternate layers of tetrahedral and octahedral FeIII ions connected by oxide and hydroxide ions. The outer shell of the complex is capped by a combination of pyridine molecules and bromide ions. Magnetic data, measured at temperatures as low as 0.4 K and fields up to 35 T, reveal competing antiferromagnetic exchange interactions; DFT calculations showing that the magnitudes of the coupling constants are highly dependent on both the Fe‐O‐Fe angles and Fe−O distances. The simplicity of the synthetic methodology, and the structural similarity between [Fe34], bulk iron oxides, previous FeIII–oxo cages, and polyoxometalates (POMs), hints that much larger molecular FeIII oxides can be made. [ABSTRACT FROM AUTHOR]

• Effects of Co-doping into ZrO 2 sol–gel films were investigated. • The surface of Co-doped ZrO 2 films showed well-ordered holes. • The E g of ZrO 2 reduces with Co doping. • Two sharp PL emission peaks were emerged at 335 and 373 nm in the PL spectra. • The magnetic behaviour of ZrO 2 film improved with Co doping. ZrO 2 is a fascinating metal oxide with rich physical phenomenon and promised applications. In this study, the effects of chemical doping with Co+2 ions on nanostructure, electronic, optical, photoluminescence (PL), and magnetic properties of Zr 1- x Co x O 2 thin films (x = 0.0, 0.05, 0.1, and 0.15) prepared by sol–gel spin-coating method were investigated. The films exhibited a tetragonal structure with crystallinity improved with Co doping. Pure ZrO 2 film showed a smooth surface morphology consisting of small particle size of 22 nm. The Co-doped ZrO 2 films exhibited well-ordered holes, and their size and number increased with Co doping up to x = 0.1 and then decreased at x = 0.15. Root-mean-square roughness increased from 1.1 nm for pure ZrO 2 to 16.5 nm for film x = 0.15. The Co ions in the films existed in a 2 + valence state. Energy band gap decreased with Co doping and had values of 4.40, 4.396, 4.392, and 4.170 eV for the films with x = 0.0, 0.05, 0.1, and 0.15, respectively. The PL spectra of films x = 0.00 and 0.05 are mainly comprised of two emission peaks; intense peak centred at 370 nm and broad peak centred about 500 nm. As the Co concentration increased, two intense and sharp emission peaks emerged at 335 and 373 nm. The films showed soft hysteresis loop, and their magnetization was enhanced with the increase of Co content. [ABSTRACT FROM AUTHOR]

Novel nano composite (ALW/CoFe2O4) adsorbent was synthesized from Apocynaceae leaf waste activated carbon (ALW) in combination with CoFe2O4by an auto combustion method for the removal of Reactive Red 141 dye and microorganisms against S. aureus, E. coli and C.albicans. The synthesized nano composite ALW/CoFe2O4 was characterized by SEM, EDX, BET, XRD, FTIR, TG & DSC and VSM. The results from these analytical techniques confirmed the aggregation of CoFe2O4 nano particles on the surface of ALW and VSM study showed its magnetic behavior. Subsequently, ALW/CoFe2O4 was adopted in batch mode adsorption studies by varying pH, adsorbent dosage, concentration and temperature. The adsorption efficiency was investigated under optimum conditions such as pH(6.5), adsorbent dosage (50 mg), contact time (70 min). The feasibility of adsorption was analyzed by fitting the data with pseudo first order, pseudo second order, Langmuir isotherm and Freundlich isotherm. The results showed that pseudo second order kinetics and Langmuir isotherm equation favour the adsorption of RR 141 on ALW/CoFe2O4. According to the thermodynamic study, it was very effective at higher temperatures and the thermodynamic parameters ∆Go, ∆Ho and ∆So were also evaluated for this adsorption. Furthermore, the antimicrobial activity of ALW/CoFe2O4 was tested by well diffusion method and compared with standard antibiotic. This ALW/CoFe2O4 exhibit good antimicrobial action with the zone of inhibition in the range of 10-17 mm. The synthesized nano composite (ALW/CoFe2O4) was evaluated for antimicrobial activityagainst (Staphylococcus aureus, Escherichia coli and Candida ablicans),usingwell diffusion methodand compared with standard antibacterial (Streptomycin) and antifungal (Amphotericin B).The antibacterial activity of ALW/CoFe2O4 against S. aureus (range between from 11.83 ± 0.23 mm to 17.5 ± 0.16 mm) and (range between E. coli 10.5 ± 0.40 to 17.0 ± 0.41 mm), while antifungistatic effectagainst C. albicans(range between 11.0 ± 0.24 to 17.6 ± 0.08), with different concentrations (100-500 mg) From the obtained results the antimicrobial activity of synthesized ALW/CoFe2O4 more or less same in the range between 11 and 17.56 mm of zone of inhibition. [ABSTRACT FROM AUTHOR]

Abstract This paper reports results on the structural stability, mechanical, electronic and magnetic behaviour of quaternary ScNiCrX (X = Al, Ga) Heusler alloys under pressure. First principles approach is applied to calculate the structural, mechanical, electronic and magnetic properties of ScNiCrX alloys under pressure. In ferromagnetic phase, both alloys (in Type-γ configuration) are stable. Over a wide pressure range, the calculations of cubic elastic constants (C ij) for both alloys fulfill the necessary criteria for structural stability. Under pressure up to 6.0 GPa, the ScNiCrAl alloy shows half-metallic ferromagnetic behaviour. The ScNiCrGa alloy exhibits half-metallic behaviour over a wide range of pressure (up to 16.0 GPa) as compared to ScNiCrAl alloy. For ScNiCrAl alloy, the spin ↓ energy band gap (E g) increases (0.27–0.43 eV) with increase in pressure (0.0–6.0 GPa) while for ScNiCrGa alloy E g increases from 0.30 to 0.58 eV with increase in pressure from 0.0 to 16.0 GPa. For pressure up to 10.0 GPa, the calculated total magnetic moment, M T (for both alloys) exhibit Slater-Pauling rule, M T = (N V – 18) μ B. Up to 6.0 GPa, it is expected for ScNiCrAl alloy to show 100% spin-polarization (at Fermi-level, E F) while for ScNiCrGa alloy, 100% spin-polarization is possible to achieve for pressure up to 16.0 GPa. On the basis of results, it is suggested that the ScNiCrX Heusler alloys could be suitable candidates for spintronic devices to operate under harsh environment. Graphical abstract Image Highlights • Quaternary Heusler alloys ScNiCrX (X = Al, Ga) are studied under pressure. • Alloys (in Type-γ configuration) are stable in ferromagnetic phase. • ScNiCrAl alloy shows half-metallic ferromagnetic behaviour for pressure ≤6.0 GPa. • ScNiCrGa alloy exhibit half-metallicity for pressure ≤16.0 GPa. • Up to 10.0 GPa, the total magnetic moment, M T follows the Slater-Pauling rule. [ABSTRACT FROM AUTHOR]

The preparation and study of new pure M 0.90 Eu 0.1‐x Dy x Zr 4 (PO 4) 6 samples with M = Sr or Ba and x = 0, 0.025, 0.050 and 0.075 was described here in detail. Currently, the luminescent emission study of this type of samples based on their tunable with the type and content of ions in the host lattice is the subject of research. These samples were synthesized by a combustion route with urea addition, followed by treatment in a reducing N 2 /H 2 atmosphere. The effect of the strontium by barium substitution and the europium by dysprosium partial substitution on the structure, powder morphology, luminescent emission and magnetic behavior was investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and magnetic measurements. X-ray diffraction patterns of the pure samples show diffraction maxima that can be assigned to a rhombohedral symmetry of space group R-3 with Z=6, compatible with a NASICON-type structure. FTIR spectra of the investigated samples show a broad band assignable to the different vibrational modes of the PO 4 3- groups. The experimental FTIR study was complemented with a theoretical study based on the SrZr 4 (PO 4) 6 structure and using different DFT methods and basis sets. Highly agglomerated spherical nanoparticles with an average particle size of about 18 nm that slightly increased with dysprosium content were found in TEM images. Broad emission bands were observed in the PL spectra of obtained samples, related to both the strontium by barium substitution and the different Eu2+/Eu3+/Dy3+ content. Magnetic susceptibility curves as a function of temperature confirm the presence of Eu2+ ions in Sr 0.90 Eu 0.1 Zr 4 (PO 4) 6 sample, and of Dy3+ ions with different Eu2+/Eu3+ ions content in the remaining M 0.90 Eu 0.1‐x Dy x Zr 4 (PO 4) 6 samples. [Display omitted] • (Sr/Ba)0.90Eu0.1-xDyxZr4(PO4)6 samples with M = Sr and Ba and with x = 0, 0.025, 0.050 and 0.075 were synthesized. • The effect of Sr by Ba substitution on the structure, size of particles and luminescent emission intensity was determined. • The effect of Eu by Dy partial substitution in the emission intensity was analyzed. • The presence of Dy3+ and Eu2+ ions with different Eu2+/Eu3+ relation was confirmed by magnetic susceptibility curves. [ABSTRACT FROM AUTHOR]

The title compound, [Co(C5H7O2)2(C6H12N2)]n, was obtained as a one-dimensional coordination polymer from bis(acetylacetonato)diaquacobalt(II), [Co(acac)2(OH2)2], and 1,4-diazabicyclo[2.2.2]octane (DABCO), a diamine with good bridging ability and rod-like spacer function. In the chain complex that extends along the c axis, the CoII atom is six-coordinated, the O-donor atoms of the chelating acac ligands occupying the equatorial positions and the bridging DABCO ligands being in trans-axial positions. In the crystal structure, the DABCO ligand is conformationally disordered in a 50:50 manner as a result of its location across a crystallographic mirror plane. The metal–metal distance is very close to that in a related compound exhibiting weak antiferromagnetic exchange between the CoII ions, and the title compound can thus be useful for obtaining more information about the contribution of different bridges to the magnetic coupling between paramagnetic ions.

Ni-Co-Mn-Sn-Cu alloys were sintered from elemental powders at a temperature of 1050 °C for 24 h. The resulting microstructures and physical properties were characterised by differential scanning calorimetry, X-ray diffraction, optical/electron microscopy and SQUID magnetometry. The use of the alloys in energy conversion was satisfactorily tested. The new alloys exhibited a distinct martensitic transformation when cooled to room temperature. The presence of Cu in the powders moved the transformation temperature toward a higher value. The findings of this study demonstrate that the powder processing could be used to replace time-consuming arc/induction melting process in the development of high performance Heusler alloys at a lower cost. [ABSTRACT FROM AUTHOR]

The full potential linearized augmented plane wave method of density functional theory has been used to investigate the structural, electronic, magnetic and thermoelectric properties of cubic perovskites BaVO and LaVO. The ferromagnetic ground state has been found to be stable by comparing the total energies of non-spin-polarized and spin-polarized calculations performed for optimized unit cells. For both compounds, the bond length and tolerance factor are also measured. From the band structures and density of states plots, it is found that both compounds are half-metallic. We found that the presence of V at the octahedral site of these perovskites develops exchange splitting through p-d hybridization, which results in a stable ferromagnetic state. The observed exchange splitting is further clarified from the magnetic moment, charge and spin of the anion and cations. Finally, we also presented the calculated thermoelectric properties of these materials, which show that half-metallic BaVO and LaVO materials are potential contenders for thermoelectric applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-step synthesis method: End products (Fe 2 O 3 and Fe 2 O 3) change depending on the precursor while maintaining the same conditions. • Low-cost, simple procedure that is good for large-scale synthesis. • Various oxides can be prepared using the specified preparation process. • Since nitrates and chlorides are abundant in industrial processes, this synthesis method can be modified to add value to the waste products produced. The two significant phases of iron oxide, namely, Hematite and Maghemite, have attracted the attention of scientists owing to their excellent magnetic and catalytic properties. Herein, we report a novel precursor salt-dependent single-step modified polyol method using the sol–gel auto combustion of metal nitrates or chlorides in ethylene glycol to synthesize magnetic alpha (α) and gamma (γ) Fe 2 O 3. The samples are then characterized to analyze the structural, morphological, electrical and magnetic properties. The XRD results show that the alpha and gamma Fe 2 O 3 exhibit hexagonal and cubic crystal structures, respectively. From the FESEM micrographs, the morphology changes are visible; for alpha Fe 2 O 3 a plate-like structure is seen, whereas the gamma Fe 2 O 3 particles exhibit a spherical morphology. The EDS spectrum indicates that the samples contain no impurity as the spectrum shows strong peaks for Fe and O. The Fe-O bond corresponding to stretching vibration is observed in the FTIR spectrum. The UV–Vis spectrum shows bandgap energy of 2.8 eV and 2.4 eV for alpha Fe 2 O 3 and gamma Fe 2 O 3, respectively. The surface of the prepared nanocomposite contains only Fe and O, which is confirmed from XPS analysis. The soft ferromagnetic behaviour of gamma Fe 2 O 3 and antiferromagnetic behaviour of alpha Fe 2 O 3 is evident from the magnetic measurements. The impedance analysis is also carried out, and the dielectric constant for alpha Fe 2 O 3 is 88, and that of gamma Fe 2 O 3 is 167. [ABSTRACT FROM AUTHOR]

Nanoparticle ferrite with chemical formula Mg (1−x) Zn x Fe 2 O 4 (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1) were prepared by sol-gel technique. Single phase structure of these ferrites was confirmed using X-ray diffraction (XRD). Transmission Electron Microscope (TEM) showed that the particle size of the samples in the range of (5.7–10.6 nm). The hysteresis studies showed superparamagnetic behaviour at room temperature. The magnetization behaviour with Zn-content is expressed in the light of Yafet-Kittel angles. The dead layer thickness (t) was calculated and its effect on the magnetization and magnetic losses was debated. The Specific Absorption Rate (SAR) in an alternating magnetic field with frequency 198 kHz for these ferrites has been studied. It is found that, the thickness of magnetic dead layer of the surface of the materials has greatly affected the SAR value of the samples. [ABSTRACT FROM AUTHOR]

The relation between conducting mechanism and magnetic behaviour of Fe-doped In 2 O 3 thin films was investigated. The films were prepared by sol gel method followed by spin coating techniques and characterized by X-rays diffractions, field emission electron microscopy, transmission electron microscopy, Hall Effect at room and low temperature, X-ray photoelectron spectroscopy and vibrating sample magnetometer. Films’ lattice parameter decreased with increasing of Fe content. Average grain size of films ranged between 8.4 and 13 nm. Oxygen vacancies of films tended to reduce with increasing of Fe doping. Films with x = 0.025 and 0.05 showed typical semiconducting behaviour while transition from metallic- to semiconducting-like behaviour was observed at 190 K and 230 K for films with x = 0.075 and x = 0.15, respectively. No trend had been found between films saturation magnetization, Ms , and free charge carriers. The magnetic behaviour of films has a correlation with localized electrons of Nearest-Neighbour Hopping conduction. [ABSTRACT FROM AUTHOR]

LiKCuP 2 O 7 compounds were obtained by high temperature solid phase method. The crystal structure, thermal behavior, infrared spectroscopy, and magnetic behavior are discussed. [Display omitted] • The 3D framework of LiKCuP 2 O 7 consists of [CuP 2 O 7 ]2- layers, with Li+ and K+ cations filling between the layers. • Magnetic susceptibility measurements over a wide temperature range suggest that the compound is antiferromagnetic. • The structure comparison of the A–Cu–P–O system and the effect of cation size on its structures have been discussed. By the application of cation substitution with a site in A–Cu–P–O (A = alkali or mixed-alkali metals) system, a mixed-alkaline metal copper-containing phosphate LiKCuP 2 O 7 has been obtained. Single crystal X-ray diffraction analysis shows that LiKCuP 2 O 7 belongs to the P 2 1 / c space group and features a three-dimensional (3D) network constructed by LiO 4 , KO 9 , CuO 5 , P 2 O 7 units. Interestingly, the CuO 5 polyhedra are interlinked with P 2 O 7 units via vertex-sharing O atoms to form two-dimensional (2D) layers, where the Li+, K+ cations reside. In order to understanding the influence of cation size on the 3D networks as well as different dimensions of Cu–P–O frameworks, the structure comparisons in the A–Cu–P–O system have been discussed in detailed. Thermal behavior and infrared spectroscopy have been analysed. What is more, magnetic susceptibility measurements over a wide range of temperature exhibit the presence of antiferromagnetic behaviour. [ABSTRACT FROM AUTHOR]

The structural stability, electronic and magnetic behaviour of YCoVZ (Z = Si, Ge) and YCoTiZ (Z = Si, Ge) Heusler alloys have been studied by first principle approach. Generalized gradient approximation (GGA) based on density functional theory (DFT) has been applied to investigate the properties of quaternary Heusler alloys. The YCoVSi, YCoVGe, YCoTiSi and YCoTiGe Heusler alloys of Type-3 structure are found to be stable in spin-polarized/magnetic phase. The YCoVSi and YCoVGe alloys exhibit nearly spin gapless semiconductor (SGS) behaviour while YCoTiSi and YCoTiGe alloys show half-metallic ferromagnetic (HMF) behaviour. For YCoVSi, YCoVGe, YCoTiSi and YCoTiGe alloys, the calculated energy band gaps in spin down ( ↓) channel are 0.60, 0.54, 0.68 and 0.44 eV, respectively. The YCoVZ and YCoTiZ alloys are found to have integral value of total magnetic moment ( M T ), thus obeying the Slater-Pauling rule, M T = ( N v –18) μ B . [ABSTRACT FROM AUTHOR]

• CaMn 0.9 Gd 0.1 O 3 fibres were obtained by LFZ under an external magnetic field (Hext) • Samples with CaMnO 3 major phase with some secondary phases were obtained. • Hext in grows direction favours phase alignment and magnetic properties. • Results show the viability to apply a Hext to other oxides tuning their properties. The perovskite-type calcium manganite exhibits interesting magnetic properties that can be tuned and enhanced by the laser floating zone (LFZ) method. This work explores, for the first time, the application of an external magnetic field during the LFZ growth of CaMn 0.9 Gd 0.1 O 3. The effects of the field direction on structural, microstructural, electrical and magnetic properties of the as-grown samples are evidenced, being observed an improvement on grain alignment and the magnetization (31.22 emu/g for 5 T at 5 K), when samples are grown under an external magnetic field in the growth direction, while the magnetic field applied in opposite direction a small improvement is observed. The results prospects to applied this process to other oxide systems for tuning their magnetic properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of doping of iron on structural, optical and magnetic properties of CeO2 nanoparticle (nps) were prepared by co-precipitation method. • Explore the various physicochemical properties and characterization of XRD, XPS analysis and UV–vis spectrometer. • Magnetic studies were done for the Observed ferromagnetic results more support this phenomenon. CeO 2 , 0.5 Fe/CeO 2 , 1 % Fe/CeO 2 , 3 % Fe/CeO 2 , and 5 % Fe/CeO 2 nanoparticles (NPs) were prepared by simple chemical co-precipitation route. The structural, morphological, and compositional analysis of the prepared samples were studied. The pristine CeO 2 is diamagnetic whereas doped samples of Fe with CeO 2 enhance ferromagnetism in CeO 2 and the hysteresis area increases up to 5 mol % of Fe. Hence, to induce a ferromagnetic behaviour in CeO 2 NPs, 5 mol % of Fe is found to be optimum. The presence of Fe3+ as found from the XPS chemical analysis to acts as an electron acceptor and/or hole donor, facilitating longer charge carrier separation in Fe-doped CeO 2. [ABSTRACT FROM AUTHOR]

Spin crossover compounds are a diverse class of switchable materials with applications ranging from data storage devices to sensors. Iron(III) spin crossover complexes have received renewed attention over the last 10 years with an increasing number of abrupt and hysteretic spin crossover systems discovered. This review provides a detailed overview of this exciting and increasingly interdisciplinary area of research with a particular focus on the structures of these materials and how this impacts their magnetic performance. [ABSTRACT FROM AUTHOR]

The title compound, [Co(C5H7O2)2 (C6H12N2)]n, was obtained as a one-dimensional coordination polymer from bis(acetylacetonato)di-aquacobalt(II), [Co(acac)2 (OH2)2], and 1,4-diaza-bicyclo[2.2.2]octane (DABCO), a diamine with good bridging ability and rod-like spacer function. In the chain complex that extends along the c axis, the CoII atom is six-coordinated, the O-donor atoms of the chelating acac ligands occupying the equatorial positions and the bridging DABCO ligands being in trans-axial positions. In the crystal structure, the DABCO ligand is conformationally disordered in a 50:50 manner as a result of its location across a crystallographic mirror plane. The metal-metal distance is very close to that in a related compound exhibiting weak antiferromagnetic exchange between the CoII ions, and the title compound can thus be useful for obtaining more information about the contribution of different bridges to the magnetic coupling between paramagnetic ions. [ABSTRACT FROM AUTHOR]

The title compound, [Co(C5H7O2)2 (C6H12N2)]n, was obtained as a one-dimensional coordination polymer from bis(acetylacetonato)di-aquacobalt(II), [Co(acac)2 (OH2)2], and 1,4-diaza-bicyclo[2.2.2]octane (DABCO), a diamine with good bridging ability and rod-like spacer function. In the chain complex that extends along the c axis, the CoII atom is six-coordinated, the O-donor atoms of the chelating acac ligands occupying the equatorial positions and the bridging DABCO ligands being in trans-axial positions. In the crystal structure, the DABCO ligand is conformationally disordered in a 50:50 manner as a result of its location across a crystallographic mirror plane. The metal-metal distance is very close to that in a related compound exhibiting weak antiferromagnetic exchange between the CoII ions, and the title compound can thus be useful for obtaining more information about the contribution of different bridges to the magnetic coupling between paramagnetic ions. [ABSTRACT FROM AUTHOR]

CoFe/Si interfacial structures have been realised by electron beam evaporation of CoFe magnetic alloy on p- and n-Si substrates. These realised interfacial structures have been characterised from X-ray diffraction (XRD), atomic force microscopy (AFM), magnetic force microscopy (MFM) and magnetisation (M–H) characteristics. XRD data have shown the presence of CoFe (bcc phase) and β-FeSi2phases for CoFe/p-Si interfacial structures, whereas CoFe/n-Si interfacial structures have shown the presence of CoFe (bcc and fcc) phases along with Fe3Si, ϵ-FeSi and β-FeSi2silicide phases having nanodimension crystallites. TheM–Hcharacteristics have shown the superparamagnetic type behaviour for CoFe/p-Si structure, whereas CoFe/n-Si structure shows a feature of interfacial antiferromagnetic (AF) coupling. The observed magnetic behaviour has been understood due to the presence of various magnetic phases and their nanosized grains. The MFM data of domain size have also been correlated with the observed magnetic behaviour. CoFe/n-Si structures have shown a significant feature of giant magnetoresistance (GMR) as compared to CoFe/p-Si structures. It has been found that CoFe/p-Si structures show a distinctly different behaviour than CoFe/n-Si structures for their chemical structure, morphology and magnetic behaviour. [ABSTRACT FROM AUTHOR]

A dinuclear compound [Mn(L)( μ-tp)](PF)⋅3.57HO ( 1) [L = N,N-(bis(pyridin-2-yl)benzy-lidene)-1,3-propanediamine and tp = terephthalate dianion] has been isolated and characterized on the basis of microanalytical, spectroscopic and other physicochemical properties. X-ray structural study showed interesting bis(bidentate) bridging motif of tp in the dicationic dinuclear unit [Mn( μ-tp)]. Each manganese(II) centre adopts a rare distorted trigonal prismatic geometry with an MnN O chromophore. Chelation of the tetradentate Schiff base (L) along with bis(bidentate) bridging of two O atoms of tp complete hexacoordination around each manganese(II) centre. The dinuclear units of 1 are associated through cooperative C-HF hydrogen bonds and π π, C-H π and rare anion π interactions to promote the dimensionality in a graded manner. Variable temperature magnetic susceptibility measurement of 1 in the 2-300 K temperature range revealed weak anti-ferromagnetic interaction presumably due to long bridging arm of tp. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: We describe the preparation, crystal structure determination, magnetic and transport properties of two novel Mn-containing perovskites, with a different electronic configuration for Mn atoms located in B site. Ca3Mn3+ 2WO9 and Ca3Mn3+/4+ 2NbO9 were synthesized by standard ceramic procedures; the crystallographic structure was studied from X-ray powder diffraction (XRPD) and neutron powder diffraction (NPD). Both phases exhibit a monoclinic symmetry (S.G.: P21/n); Ca3Mn2WO9 presents a long-range ordering over the B sites, whereas Ca3Mn2NbO9 is strongly disordered. By “in-situ” NPD, the temperature evolution of the structure study presents an interesting evolution in the octahedral size (〈Mn–O〉) for Ca3Mn2NbO9, driven by a charge ordering effect between Mn3+ and Mn4+ atoms, related to the anomaly observed in the transport measurements at T≈160K. Both materials present a magnetic order below T C =30K and 40K for W and Nb materials, respectively. The magneto-transport measurements display non-negligible magnetoresistance properties in the paramagnetic regime. [Copyright &y& Elsevier]

This paper describes a multidisciplinary study approach (petrography and rock magnetism) conducted on samples collected from the study area to characterise the magnetic mineralogy and to determine if the magnetisation of both lithologies were induced or retain a remnant component. Petrophysical, mineralogical and geochemical analyses confirm bimodal aspects, particularly in basic rocks; the two magnetic modes depend essentially on the mineralogical and geochemical characteristics of the samples. The ultramafic rocks comprise a highly altered primary mineralogy with chromite and magnetite as magnetic phases. The second type is of mafic composition with a less altered primary mineralogy and essentially magnetite and/or (hemo-ilmenite) as a carrier of magnetic mineralisation. Sulphides are characterised by high concentrations of Cu, Zn and Pb. The mineralogy is composed mainly of pyrrhotite (85% to 90%), sphalerite, galena, chalcopyrite, arsenopyrite and, occasionally, stannite. Monocline pyrrhotite seems to be the magnetic carrier of magnetisation in both Draa Sfar and Koudiat Aïcha. However, we suspect a different amount of hexagonal pyrrhotite as the cause of different magnetic behaviour. Paleomagnetic and thermomagnetic analyses reveal different. The calculated characteristic direction of natural remnant magnetisation for sulphides was used to model the magnetic anomaly of Draa Sfar. The proposed model match the geological features concluded from geological mapping and boreholes. Results from this work can be very useful for any modelling processes of magnetic anomalies suspected due to a sulphide mineralisation in an area with poor outcrops and no presence of boreholes information or of any geological or geochemical data. [ABSTRACT FROM AUTHOR]

Abstract: The union of nanotechnology with the other fields of science heralds the influx of many newer and better technologies, with the capability to revolutionize the human life. In the present work, calcium ferrite nanoparticles were synthesized by conventional sol–gel method and were characterised by X-ray diffraction, Transmission electron microscope, Vibrating sample magnetometer and Fourier transform infrared spectroscope. The synthesized nanoparticles were calcined at different temperatures and their magnetic behaviour was studied. The synthesized nanoparticles calcined at 900°C were formed in the shape of capsules and exhibited mixed characteristics of ferrimagnetic and paramagnetic grains with magnetic saturation of 0.85emu/g whereas nanoparticles calcined at 500°C were spherical in shape and exhibited superparamagnetic characteristics with saturation magnetization of 37.67emu/g. [Copyright &y& Elsevier]

Abstract: The synthesis, X-ray structure and magnetic properties of two new zoledronato complexes are presented: Mn(II)(H3Zol)2(H2O)2, (I) and Fe(III)15(HZol)10(H2Zol)2 (H2O)24 (2/3Cl:1/3H2O)6·7Cl·65(H2O) (II), where H4Zol=zoledronic acid=C5H10N2O7P2. Complex (I) is a dimer, built up around an inversion centre where the cation is located, surrounded by two chelating zoledronate anions and two water molecules. The structure is isomorphous to the Co, Ni and Zn isologues. A quite different structure is the Fe(III) complex which consists of a centrosymmetric cluster with 15 Fe(III) cations (one of them at the inversion centre), 12 zoledronate anions, in different protonation states and 26 coordinated water molecules, 24 of which show full occupancy and the remaining 2 share 6 coordination sites with 4 chlorine anions. There are in addition 7 chlorine counterions and a not well determined number of hydration water molecules, their number being adjusted as to match the chemical and TGA analysis. The general shape of the molecule is that of a 6 arm propeller with a Fe(III) cation at its center and two FeO6 coordination polyhedra sitting above and below, defining some sort of “paddle wheel axis”, perpendicular to the wheel plane. Around this axis there is an almost perfect circular structure formed by other six FeO6 octahedra, to which the “paddles”, defined by the remaining six FeO6 groups attach. The ensemble presents some unusual (Fe···OPO) n loops (n =2,3,4), some of them unreported, and displays a striking non-crystallographic −3 symmetry. The protonation state of the zoledronato ligands were inferred from the counterions effectively found and charge balance considerations. Both compounds present a paramagnetic behaviour at R.T, and obey a Curie Weiss law down to rather low temperatures (15K for (I), 100(K) for (II)) with a tendency to different types of interactions viz., ferromagnetic for (I) and antiferromagnetic for (II). The geometry of the F15 cluster is analyzed. [Copyright &y& Elsevier]

The organic-inorganic coordination polymer of the general formula {[NiL][Co(NCS)]} (where L = 5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene) has been synthesized and characterized by IR, UV-Vis, DSC/TG, DTA/TG/MS methods. The magnetic behaviour of this complex has also been investigated within the temperature range 1.8-300 K. The IR spectrum indicates the presence of bridging M-NCS-M′ ligands. The absorption bands of UV-Vis spectrum confirm that the coordination environment of nickel(II) ions changes from square planar for [NiL](ClO) to octahedral for {[NiL][Co(NCS)]}. The obtained compound is stable at room temperature, but within the range 246-282 °C decomposes in a three-stage process. The first step is associated with decomposition of the coordination polymer to the cationic [NiL] and anionic [Co(NCS)] units; the next two stages correspond to gradual decomposition of the macrocyclic ring. The value of molar magnetic susceptibility (χ T = 2.16 cm molK) indicates that the compound is paramagnetic. [ABSTRACT FROM AUTHOR]

A new iron(II) coordination polymer, [FeCl(NCH)(NCH)], has been synthesized under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction. This material crystallizes in the monoclinic space group C2/c, with a = 11.2850(6), b = 13.8925(7), c = 17.0988(9) Å and β = 94.300(3)º ( Z = 4). The crystal structure consists of neutral zig-zag chains, in which the iron(II) ions are octahedrally coordinated. The infinite polymer chains are packed into a three-dimensional structure through C-H···Cl interactions. Magnetic susceptibility measurements reveal the existence of weak antiferromagnetic interactions between the iron(II) ions. The effective magnetic moment, μ = 5.33 μ, is consistent with a high-spin iron(II) configuration. Graphical Abstract: The crystal structure of the coordination polymer [FeCl(NCH)(NCH)] consists of neutral zig-zag chains, in which the iron(II) ions are octahedrally coordinated.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: We have investigated the crystal structure, magnetic and electrical transport properties of the new ternary compound Eu20Ni42As31, crystallizing in the hexagonal Sm20Ni42P31 structure type, space group P63/m, a =21.1496(7), c =4.0734(2)Å, according to X-ray powder diffraction. From magnetic investigations it is evidenced that in this compound the europium is divalent, Eu2+. The compound orders antiferromagnetically at a Neèl temperature T N =5K. However, in moderate magnetic fields an overall ferromagnetic-like magnetization is observed. The measurements of the electrical resistivity prove this magnetic behaviour as well as the metallic character of the compound Eu20Ni42As31. [Copyright &y& Elsevier]

Abstract: The monoanionic Ni, Au and Cu bisdithiolene complexes based on the 1-(pyridin-4-yl)-ethylene-1,2-dithiolate were prepared and isolated as [PPh4]+, [n-Bu4N]+ and [Na(18C6)]+ salts which were characterised by single-crystal X-ray diffraction, cyclic voltammetry, EPR and magnetic susceptibility measurements. All the complexes adopt a square planar coordination geometry with a trans arrangement of the substituent pyridine rings whose planes are rotated from 13° to 33° relatively to the central MS4 core. The C–C and C–S bond lengths are consistent with ene-1,2-dithiolate form of the ligand and MIII oxidation state. The Ni complexes are paramagnetic with an effective magnetic moment of ∼1.7BM. [Copyright &y& Elsevier]

Abstract: A manganese(II) complex with N,N′-bis(carboxymethyl)dithiooxamide (H4GLYDTO), [Mn(H2GLYDTO)(H2O)2] n , has been synthesized and characterized by elemental analysis and thermogravimetric analysis, as well as by infrared, electronic and EPR spectroscopy and magnetic susceptibility measurements. The crystal and molecular structure of this complex was determined by single-crystal X-ray structure analysis. The compound shows a 3D porous framework with alternate left- and right-handed helical channels where the manganese(II) ions have an octahedral environment. Variable temperature magnetic measurements reveal the existence of very weak antiferromagnetic interactions through the syn-anti carboxylate bridge, with an exchange parameter of J/k =−0.12K. [Copyright &y& Elsevier]

• Introduction to a method measuring temperature dependent magnetic properties. • Post-determination of primary microstructure of 50CrMo4 after QT heat treatment. • Precise hardness estimation choosing the right measurement parameters. • Correlation between the effect of different precipitations and magnetic properties. • Categorisation of the effect of eddy-currents on the B-H hysteresis. This work investigates the effect of different initial microstructures on the electromagnetic magnetisation curves/hysteresis of 50CrMo4 steel and technically pure iron introducing a novel measurement method. Surprisingly little is known about the relationship between microstructure and the magnetic properties, although this is of great importance for a better understanding and multi-physics modelling of induction heat treatment. Analysis of the magnetic hysteresis and Distortion Analysis of Magnetic Excitation (DAME) are important techniques to characterise magnetic behaviour of materials. To perform these measurements, a specific measurement setup based on excitation circuit/yoke with secondary coils was implemented. Using these methods, the characterization of the effect of mechanical properties (i.e.: hardness) and different microstructures on electromagnetic magnetisation curves/hysteresis is possible with high precision. The effect of the eddy-currents on the B-H hysteresis shows a systematic behaviour, which opens the possibility for a new kind of categorisation of these effects. DAME shows a closely linear relationship with the assumed precipitation size allowing indirect analysis of the microstructure, also at elevated temperatures. [ABSTRACT FROM AUTHOR]