The fluorescence effect induced by Kβ photons is usually so small that it can be neglected. However, in the Fe–Mn system, omitting Kβ fluorescence correction will lead to the overestimation of the Mn content especially when Mn is the minor alloy element. In this study, the error in the Mn concentration induced by Kβ fluorescence was investigated by both Monte Carlo simulation, using the pyPENELOPE program, and systematic electron probe measurements on the Fe–0.53% Mn alloy standard by the aid of CalcZAF software. It is shown that the error caused by Kβ fluorescence exceeds 4% for the Fe–0.53% Mn alloy. The problem can be overcome by utilizing CalcZAF in which β-line fluorescence has been included, or by employing a similar standard Fe–0.85% Mn for Mn in the absence of β-line fluorescence correction. In addition, a modified calibration curve method, using k-values instead of X-ray intensity as a variable, is presented and used to measure the Mn concentration. The accuracy of this method is as good as or better than that of the conventional matrix correction method. Compared with conventional calibration curve methods, it is time-saving because the k-value is not sensitive to instrument fluctuations and the established curve remains valid for a long period.

We present density functional theory calculations to study the interplay between magnetic and structural properties in Ni-Co-Mn-Sn. The relative stability of austenite (cubic) and martensite (tetragonal) phases depends critically on the magnetic interactions between Mn atoms. While the standard generalized gradient approximation (GGA) stabilizes the latter phase, correlation effects beyond GGA tend to suppress this effect. Mn atoms treated as magnetic impurities can explain our results, where a delicate balance between magnetic interactions mediated by Ni d and Sn p orbitals determines the equilibrium structure of the crystal. Finally, we discuss the role of Co doping in stabilizing ferromagnetic austenite phases.

We report on photo-induced magnetic effect and infrared (IR) spectroscopic behavior of colossal magnetorestive manganite La0.7Sr0.3MnO3 (LSMO) with rare earth co-doping (Er3+ and Yb3) at room temperature. X-ray diffraction shows that a structural phase transformation from rhombohedral to hexagonal with increasing Er and Yb concentrations. Photo-induced magnetoresistance showed that Er3+ and Yb+3 ions have significant influence on the magnetic and electrical ordering of LSMO under the influence of UV light. The optical excitation also shows an enhancement in the magnetotransport properties of LSMO.

Supercapacitors have the potential to complement or replace batteries in many current and emerging applications. As inexpensive and environmentally benign capacitive materials, manganese oxides are promising electrode materials. Nanostructured oxides have high energy storage capacities owing to their increased surface-area-to-volume ratios as compared to bulk materials. By electrospinning precursor-containing polymer fibers and subsequently calcining, nanostructured MnOx fibers can be prepared with relative ease. Controlling calcination pressure and time provides a route for variable capacitance via modifying surface roughness and oxide phase. At moderate pressures and short calcination times, mixed-phase Mn2O3/Mn3O4 fibers with high surface roughness exhibit enhanced electrochemical specific capacitance.

The crystal-chemical mechanisms by which transition metals are associated with goethite are fundamental to our understanding of the solubility and bioavailability of micronutrients and heavy metals in soils, and in the formation of laterite ore deposits. Transition metals such as Cr, Mn and Ni may sorb onto goethite by forming surface precipitates, surface complexes or by replacing Fe3+ in the goethite structure. In the work reported here, we investigated the local coordination environment of Cr, Mn and Ni in synthetic goethite using EXAFS spectroscopy. We demonstrate the isomorphous substitution for Fe3+ by Cr3+ (up to 8 mol.%), Mn3+ (up to 15 mol.%) and Ni2+ (up to 5 mol.%). We find, however, that the next-nearest-neighbour coordination environment changes with composition. The perturbations are likely to be responsible for limiting the accommodation of Cr3+, Mn3+ or Ni2+ in the FeOOH structure.

Eutectic Al–13% Si alloys are widely used in automotive components, such as pistons and cylinder heads. Recently, the demand on the performance of piston alloys at high temperature is greatly increased to enhance the engine efficiency and to reduce exhaust emission. In the present work, Mn was added to strengthen the aluminum matrix via the formation of thermally stable dispersoids. The evolution of dispersoids during heat treatment and their influence on elevated-temperature properties were studied. The results showed that the as-cast microstructures in the experimental alloys without/with Mn addition were similar, which were composed of eutectic Si, primary Mg2Si, Al–Fe–Ni, Al–Cu–Ni, and π-Al–Mg–Fe–Si intermetallic phases. In the alloy with Mn addition, a number of α-Al(Mn,Fe)Si dispersoids started to form after a heat treatment at 425 °C for 24 h and reached the peak condition at 500 °C for 6 h, resulting in a remarkable increase of the microhardness at room temperature and the improvement in the yield strength and creep resistance at 300 °C. As a complementary strengthening mechanism, the dispersoid strengthening in the aluminum matrix provides a novel approach to improve the elevated-temperature properties of Al–Si piston alloys.

The effect of tunnel cations on tunnel size in α-MnO2 structured (hollandite, cryptomelane) materials has long been of interest, as the tunnel size effects catalytic and transport properties. Previous research on the tunnel size has focused on potassium cryptomelane (KxMn8O16). This paper uses synthetic control of silver content in AgxMn8O16 to investigate the effect that tunnel silver occupancy has on the lattice parameters. Materials with silver (x) content between 1.14 and 1.66 were synthesized, synchrotron diffraction and Rietveld Refinement was used to determine lattice parameters. The lattice parameters were found to contract as silver content increases (from 9.774 Å to 9.738 Å), in contrast to previous investigations of other tunnel cations.

Highly detailed structural characterization is required to understand the discharge mechanism in order to effectively investigate α-MnO2 structured lithium battery cathode materials. This paper discusses recent findings which elucidate the lithiation mechanism of silver-hollandite, AgxMn8O16. For Ag1.2Mn8O16, the structure is not significantly perturbed during the first 2 equivalents of lithiation and the electrochemistry is highly reversible. Upon 4 equivalents of lithiation, the structure becomes highly distorted, in correlation with capacity fade observed over 40 cycles. Notably, regarding capacity fade, modifications to Ag/Mn ratio are less impactful than modifications to the α-MnO2 crystallite size. This is shown in comparisons of two materials with the same stoichiometry (Ag1.4Mn8O16) and differing crystallite size (10 and 15 nm).

Manganese (Mn) and rare-earth elements (REEs) in a stalagmite (SJ3) collected from Central China were analyzed, using an ICP-MS method for the precise determination of > 40 trace elements in geological samples by enriched-isotope internal standardization. Unlike speleothem Mn and REEs investigated by cathodoluminescence, which may be incorporated into crystal lattice, the Mn and REEs analyzed in SJ3 should come largely from colloidal and particle phases in groundwater and may be associated with non-carbonate inclusions. The Mn and REEs in SJ3 vary significantly during the period between 20 and 10 ka. These elements show remarkable increases since ∼ 14.5 ka, suggesting enhanced weathering of the overlying soil layer and the host rock since the onset of the last deglaciation and the strengthening of the Asian summer monsoon. In addition, the Mn and REEs in SJ3 display significant centennial fluctuations which may reflect groundwater dynamics.

This work presents the effects of sintering temperature and mechanical milling on the weight loss of the powder metallurgical Fe–28Mn–3Si (wt%) alloy. Mechanically milled (MM) and blended elemental (BE) Fe–28Mn–3Si powder mixtures were prepared. Both the MM and BE compacts were sintered in a vacuum furnace for 3 h at various temperatures. It was found that weight loss occurred among all the sintered compacts. The weight loss of the sintered MM compacts was much lower than their BE counterparts sintered at the same temperature. The weight loss of the compacts was mainly caused by the sublimation of Mn in the Mn depletion region. A single α-Fe phase was observed on the surface of all the sintered samples. Predominant γ-austenite and minor ε-martensite were detected in all the sintered compacts at locations beyond the Mn depletion region. Mn3Si phase was found in BE alloys sintered at 1000 °C.

Cryptomelane type manganese dioxides (α-MnO2, OMS-2) are interesting potential cathode materials due to the ability of their one dimensional (1D) tunnels to reversibly host various cations including Li+ and an accessible stable 3+/4+ redox couple. Here, we synthesized metal cation free OMS-2 materials where the tunnels were occupied by only water and hydronium ions. Water was subsequently removed from the tunnels. Cation free OMS-2 and Dry-OMS-2 were used as cathodes in Li based batteries to investigate the role of tunnel water on their electrochemistry. The initial discharge capacity was higher for Dry-OMS-2 (252 mAh/g) compared to OMS-2 (194 mAh/g), however, after 100 cycles Dry-OMS-2 and OMS-2 delivered 137 mAh/g and 134 mAh/g, respectively. Li+ ion diffusion was more facile for Dry-OMS as evidenced by rate capability, at 400 mA/g. Dry-OMS-2 delivered 135mAh/g whereas OMS-2 delivered ∼115 mAh/g. This first report of the impact of tunnel water on the electrochemistry of OMS-2 type materials demonstrates that the presence of tunnel water in OMS-2 type materials negatively impacts the electrochemistry.

Water-splitting by using electric power produced by solar cells is promising system to produce hydrogen without fossil fuels. Oxygen evolving catalyst is, however, major problem to prevent using this system widely because precious materials are used in the catalyst. Considering from the photosynthesis II of plants, the compound of Ca-Mn-O is one of the candidates for the oxygen evolving catalyst. In this study, the synthesis condition and the oxygen evolving electrocatalytic activity of CaMn2O4•xH2O are investigated. The overpotential at 0.1 mA/cm2 was 0.28 V when using the electrode of carbon paste and CaMn2O4•H2O with the weight ratio of 3:1.

Manganese oxide based nanoparticles were synthesized by sol-gel process. Methanol, ethanol, and propanol were used as alternative solvent during sol-gel process with manganese acetate as precursor for the preparation of pristine manganese oxide. Hybrid MnOx modified by additions of carbon nanotubes was further prepared. Smallest particle size was observed for manganese oxide prepared from propanol, with diameters range from 16 nm to 50nm. XRD results showed that the as prepared manganese oxide based samples at calcination temperature of 300°C and above were composed of Mn2O3 as dominant phase, with Mn3O4 as minor phase. Specific capacitance measured from two electrode systems of manganese oxide prepared from methanol, ethanol, and propanol at scan rate of 10 mV/s were 88.3, 66.0, 104.8 F/g and the result for the hybrid sample was 140.5 F/g. The highest capacitance of the MnOx revealed a specific capacitance of 231.4 F/g when a 1:1 mixture of propanaol and methanol was employed as the solvent for the sol preparation. Results from electrochemical impedance spectroscopy (EIS) also showed superior electrochemical properties of the hybrid sample over pristine manganese oxide samples.

We have investigated characteristic ferroelectric and structural antiphase domain structures in single crystals of hexagonal RMnO3 (R=Y, Ho, Lu, and Yb) by obtaining various electron diffraction patterns, dark-filed images and high-resolution lattice images. In the ferroelectric phase of RMnO3 characteristic domain structures consisting of six ferroelectric and structural antiphase domains, which can be identified as the “cloverleaf” pattern, is found in the (110) plane, in addition to the (001) plane, and are inherent to the ferroelectric phase of hexagonal RMnO3. In domain configuration with the cloverleaf pattern in the (110) plane, the structural antiphase boundaries are inclined to be parallel to the [001] direction.

Porous CoO/Mn2O3 Fischer-Tropsch (F-T) catalysts have been studied in CO hydrogenation. These CoO/Mn2O3 catalysts have been synthesized by incipient wetness impregnation method. These mesoporous catalysts have pore diameters of 2-25 nm and a surface area of 9.0 m2/g. The gas and liquid products have been analyzed by an online gas chromatograph. The solid products were characterized by gas chromatograph-mass spectroscopy. These microsize cobalt catalysts exhibit good activity with 72.1% CO conversion and they are very stable in a 48 h stream test at 280ºC. The selectivity to paraffins is above 95%. Few wax products were synthesized with a yield of less than 2%. The size effects of the cobalt catalysts have been studied by scanning electron microscopy.

MnO nanoparticles were surface modified using two different multifunctional polymers. By introducing a PEG group, the long term stability, MRI applicability and sterile filtration could be greatly improved. Furthermore, PEGylated MnO NPs were less toxic compared to non-PEGylated NPs. The results suggest that these nanoparticles are suitable for in vivo applications.

In order to realize the magnetic refrigeration system, it is necessary to develop a 100 W class refrigerator with COP > 7.5. This requires us to find new magnetic refrigerant materials, of which cooling capacity is 2.5 times higher than that of Gd. In this paper, first we discuss the cooling capacity of magnetic refrigerant materials to achieve COP = 7.5. Then, we compare the experimental results of MnAsSb, MnFe(PGe) and La(FeCoSi)13 compounds with the calculated cooling capacity. It is suggested that a composite layer material of MnFe(PGe) would show excellent cooling capacity in the temperature span of 20 K.

This paper introduces a highly reliable Cu interconnect technology at the 32 nm node with CuMn alloy seed. A CuMn alloy liner seed process combined with a non-gouging liner has been integrated into the minimum-pitch wiring level. Stress migration fails with CuMn seed at plate-below-via structures were shut down by a non-gouging liner process. Integration with gouging liner and non-gouging liner is compared, and results of interaction with CuMn seed are discussed in this paper.

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

The past decade has witnessed a great interest in single molecule magnets (SMM) especially those based on manganese such as Mn12-acetate due to their potential applications in ultrahigh density data storage and quantum computing devices. The focus so far has been in finding different derivatives of Mn or other complexes based on transition elements in order to raise the blocking temperature of single-molecule magnets (SMMs). Herein we propose a fundamentally new approach of generating new category of SMMs through formation of composite structures by binding SMMs on to nanoparticles. In this report, we present the synthesis and characterization of single molecular magnet - gold nanoparticle composite- Mn12-cysteinate functionalized gold nanoparticles.