Ternary Mn Research Articles

2-(2-Pyridyl) benzimidazole-based ternary Mn(ii) complex as an arsenate selective turn-on fluorescence probe: ppb level determination and cell imaging studies

2-(2-Pyridyl) benzimidazole based ternary Mn(II) complex (MnPBINCO) is established as an arsenate selective turn-on fluorescence probe in HEPES buffered (0.1 M, methanol/water = 0.5/99.5, v/v, pH 7.4) solution for the first time. MnPBINCO can determine the presence of HAsO42− at concentrations as low as 1 × 10−10 M and efficiently detect intracellular HAsO42− under a fluorescence microscope.

Corrigendum to “The experimental investigation of phase equilibria in the Al-rich corner within the ternary Al–Mn–Be system” [J. Alloys Compd. 570 (2013) 125–132

Corrigendum to “The experimental investigation of phase equilibria in the Al-rich corner within the ternary Al–Mn–Be system” [J. Alloys Compd. 570 (2013) 125–132

PH-controlled solid-phase enrichment of Mn(II): confirmation of the structure of the extracted ternary Mn(II) complex by single crystal X-ray structure analysis

Trace-level (μg g−1) selective separation of Mn(II) from other associated metal ions have been carried out by impregnating equimolar mixture of pyridine-2, 6-dimethanol (PDM) and thiocyanate ion on silica. The sorbent showed maximum Mn(II) sorption capacity (1.23 mmol g–1) at pH 5.0. Mn(II) was completely eluted by 8.5 mL 1.0 mol L−1 HNO3 from 1.0g sorbent and subsequently measured with flame atomic absorption spectrometer (FAAS).The structure of the extracted Mn(II) complex was established by Fourier transform infrared red spectra and confirmed by single crystal X-ray structure analysis. Thermogravimetric analysis (TGA) shows the stability of the isolated Mn(II) complex at the extraction temperature. Three sigma detection limit (N = 10) of the method was 0.6 μg mL−1 with a relative standard deviation of 0.1% (N = 10). The method has a pre-concentration factor of 105. Marginal interference from Cu2+ has been masked with NH4SCN. The developed method has been tested for trace-level separation and estimation of Mn(II) in spiked water samples.

Li‐Doped Cr2MnO4: A New p‐Type Transparent Conducting Oxide by Computational Materials Design

AbstractTo accelerate the design and discovery of novel functional materials, here, p‐type transparent conducting oxides, an inverse design approach is formulated, integrating three steps: i) articulating the target properties and selecting an initial pool of candidates based on “design principles”, ii) screening this initial pool by calculating the “selection metrics” for each member, and iii) laboratory realization and more‐detailed theoretical validation of the remaining “best‐of‐class” materials. Following a design principle that suggests using d55 cations for good p‐type conductivity in oxides, the Inverse Design approach is applied to the class of ternary Mn(II) oxides, which are usually considered to be insulating materials. As a result, Cr2MnO4 is identified as an oxide closely following “selection metrics” of thermodynamic stability, wide‐gap, p‐type dopability, and band‐conduction mechanism for holes (no hole self‐trapping). Lacking an intrinsic hole‐producing acceptor defect, Li is further identified as a suitable dopant. Bulk synthesis of Li‐doped Cr2MnO4 exhibits at least five orders of magnitude enhancement of the hole conductivity compared to undoped samples. This novel approach of stating functionality first, then theoretically searching for candidates that merits synthesis and characterization, promises to replace the more traditional non‐systematic approach for the discovery of advanced functional materials.

Influence of Mn and Zr on the Corrosion of Al-Free Mg Alloys: Part 2—Impact of Mn and Zr on Mg Alloy Electrochemistry and Corrosion

A total of 47 alloys were produced to explore the changes in electrochemical and corrosion behavior of binary and ternary Mn- and Zr-containing Mg alloys—in the absence of Al. Up to ~2 wt% Mn was found to slightly reduce cathodic kinetics, while Zr in solid solution increased anodic reaction kinetics. We demonstrate that Zr is an efficient “activator” of Mg, which has not been explicitly shown previously. When Mn and Zr are both added to Mg, there can be an optimized combination/interaction where Mn with Zr works in conjunction to moderate the corrosion rate compared to an Mg-alloy with either Zr or Mn as singular additions. This has ramifications in emerging Al-free Mg alloys.

Thermodynamic assessment of the Mn–Ni–O system

Abstract Experimental data on thermodynamic properties and phase relations of the ternary Mn–Ni–O system were reviewed, and by use of the CALPHAD method, a consistent set of model parameters was optimised. The solid oxide phases were modelled using the compound energy formalism. The model allows representation of non-stoichiometry and solid solution in the phases. The distribution of cations between different lattice sites in the two spinel phases is also modelled. The liquid phase is described using the ionic two-sublattice model. The same model is used both for the metallic and the oxide liquid. Good agreement between calculated and experimental values is achieved.

Hydrothermal origin of manganese in the high-pressure ophiolite metasediments of Praborna ore deposit (Aosta Valley, Western Alps)

The manganese ore deposit of Praborna crops out in the Zermatt-Saas unit of the Western Alps, in the St. Marcel valley. It represents a Jurassic ophiolitic sedimentary cover subducted at high-pressure conditions during the Alpine orogeny. Major- and trace-element analyses of representative samples of the ore and the host metasediments were collected to geochemically characterise the deposit. Selected phases (piemontite, braunite, garnet, clinopyroxene, white mica and manganiandrosite) were investigated with ion and electron microprobes to link the mineral chemistry to the bulk-rock chemistry. Compared to shales, Praborna is enriched in Mn (up to 38.7 wt% Mn 2 O 3 ) and in many trace elements (Sc, Co, Ni, Cu, Ge, As, Sr, Ag, Sb, Te, Ba, Tl, Pb and Bi). The bulk-rock REE pattern suggests 20 % hydrogenous and 80 % hydrothermal inputs in the proto-ore. Compared to the shale, the hanging-wall Mn-poor schists share with the Mn ore body the enrichment in Sc, Mn, Co, Sr and Te, suggesting a common enrichment process involving these elements. The REE pattern suggests a sedimentary origin for these schists, which were probably composed of clay mixed with components of volcanic origin. In order to confirm the hydrothermal origin of the Praborna Mn ore deposit, we built up a database of more than 5000 data of modern hydrogenous and hydrothermal oceanic Mn deposits worldwide, adding data of oceanic Mn-rich sediments and of the Ligurian Mn ore deposits, which are thought to be the unmetamorphosed geological equivalent of Praborna. The classic ternary Mn–Fe–(Cu + Co + Ni) diagram, the agglomerative hierarchical clustering and the principal-component analysis, which takes into account a larger set of elements, strongly support the hypothesis of an oceanic hydrothermal origin for manganese in the Praborna and in the Ligurian ore deposits.

Interfacial Microstructure and Strength of Vacuum Brazed Joints of Ternary Ceramics Ti<sub>3</sub>SiC<sub>2</sub>

Ti3SiC2 is one of the nano-layered ternary ceramics Mn+1AXn, where M is a transition metal, A is an A-group (mostly IIIA or IVA) element, and X is C or N. With the filler of Ag-Cu-Ti, the brazing of Ti3SiC2 has been conducted at 800°C–950°C for 5-10min under 3.5×103Pa in a vacuum. The phase composition and microstructure of the joints were investigated by XRD, SEM AND EPMA. The diffusion of Cu element in fillers through the reaction zone toward Ti3SiC2 is the main controlling step in the bonding process. Joint strengths were evaluated by three point bending test. The maximum flexural strength of joints reaches is 306±11MPa, which is lower than the bending strength of Ti3SiC2, obtained under the same condition.

Infrared detectors based on thin film thermistor of ternary Mn–Ni–Co–O on micro-machined thermal isolation structure

Experimental studies on preparation of thin films of ternary compositions of Mn 3O 4, NiO and CoO using ion beam sputtering technique and electrical properties characterization have been carried out. The compatibility of thin films deposited on thermally grown silicon oxide on Si wafer of <1 0 0> orientation to produce thin film thermistors on a thermal isolation structure (TIS) by wet chemical micro-machining process has also been investigated. It is observed from energy dispersive X-ray (EDAX) analysis that the chemical compositions of thin films have close proximity to the target composition, with minor deviations in the individual oxide contents. While the films whose manganese oxide content is higher and nickel oxide lower, have higher thermistor constant 3600 K, and sheet resistance 4×10 7 Ω/sq, the films which have lower manganese oxide and higher nickel oxide are found to have medium thermistor constant 2186 K, and lower sheet resistance 5×10 5 Ω/sq. The micro-machined TIS, analyzed by scanning electron microscope, is observed to have an isolated bridge structure. The voltage–current relationship of the sensor element deposited on the TIS is linear up to an applied bias of 10 V, and the thermal conductivity and the thermal mass of the entire bridge structure are respectively 2.6×10 −6 W K −1 and 1.3 × 10 −9 J K −1. The responsivity, and detectivity of the infrared detector fabricated, using thin film thermistor sensor deposited on a micro-machined TIS together with a suitable infrared absorber coating, are respectively equal to 3000 V W −1 and 4.4×10 8 cm Hz 1/2 W −1 at 10 Hz operating frequency, and the time constant is 0.53 ms.

A neutron diffraction study of the hexagonal pseudo-ternary compounds ErMn 6− xFe xSn 6 ( x = 0.2, 0.4, 0.6, 0.8, 1.0, 2.0, 3.0, 4.0)

The hexagonal ErMn 6− x Fe x Sn 6 solid solution (0.2 < x < 4) has been studied by magnetisation measurements and neutron diffraction. The ordering temperature of the T = (Mn,Fe) sublattice almost continuously increases from T = 386 K for x = 0.2 to T = 498 K for x = 4. The T sublattice orders in the successive magnetic structures helimagnetic H1, antiferromagnetic AF2, helimagnetic H2 and antiferromagnetic AF1 with increasing iron content. While structures AF2 and H1 were already observed in ternary Mn compounds and AF1 in ternary iron compounds, the structure H2 is of a new kind characterized by an AF slab around the Er(1a) site. At low temperature, a change of the easy direction of the Er moment from easy plane to easy axis is observed. The iron-rich compounds display a ferromagnetic order of the Er sublattice. A new kind of magnetic structure characterized by a sine-wave modulated arrangement with a propagating vector Q = (0, 0, q z ) is also observed. The evolution of the magnetic properties (enhancement of the AF character of the (Mn,Fe) sublattice and magnetocrystalline anisotropy of erbium) is discussed.

Correlation between site preference of ternary Mn addition in LaAg and superconductivity

Investigation of structure, surface morphology, composition, and the superconducting-normal phase diagram of LaAg1−cMnc superconducting alloys with nominal composition c=0.0, 0.025, 0.05, 0.1, 0.2, and 0.3, reveals the following. The alloys with c=0, 0.025, and 0.05 are essentially single phase alloys with the actual Mn concentration x same as the nominal one, i.e., c=x, whereas in the alloys with c=0.1, 0.2, and 0.3, the actual Mn concentration of the majority phase (crystalline grains) is x=0.050(1), 0.080(1), and 0.100(1), respectively. The ternary Mn addition does not alter the CsCl structure of the parent compound LaAg. Neither a structural phase transition nor a long-range antiferromagnetic order is observed at any temperature in the range 1.8 K≤T≤50 K in any of the Mn containing alloys. Mn has exclusive La (Ag) site preference in the alloy (alloys) with x=c=0.025 (x≥0.05 or c≥0.1) whereas in x=c=0.05, Mn has essentially no site preference in that all the Mn atoms either occupy the La sites or the Ag sites. When Mn substitutes for La at the La sublattice sites (as is the case in x=c=0.025), conventional phonon-mediated (BCS) superconductivity prevalent in the parent LaAg compound is destroyed but when Mn replaces Ag at the Ag sublattice sites (as in x≥0.05), non-BCS superconductivity at elevated temperatures is observed.

Thick film NTC thermistor for wide range of temperature sensing

PurposeAims to focus on temperature sensors.Design/methodology/approachNegative temperature co‐efficient thermistor powders of ternary Mn, Co, Ni oxide along with RuO2 synthesized at relatively moderates temperature (1,000°C). Thick film thermistor paste compositions were formulated by mixing the semiconducting oxide powder, glass frit and organic vehicle. The physico‐chemical analysis, viz. X‐ray diffraction, scanning electron microscopy and thermogravimetry and IR spectroscopy were carried out for the synthesized powder and the resultant thick films. The X‐ray analysis of the powders showed the cubic spinel structure. The electrical properties like thermistor constant, sensitivity index and activation energy of the thick film NTC thermistor were determined.FindingsThe room temperature resistance is observed to range from 490 KΩ to 4.13 MΩ with thermistor constant ranging from 3,275 to 3,980 K, in the temperature range of 25‐300°C.Originality/valueDescribes research work on temperature sensors that are used for monitoring and control in many fields such as in home appliances, manufacturing industries, biomedical and automobile industries.

Magnetic properties of [formula omitted]-MnCoZn alloys

We have found that the β -Mn phase in the ternary Mn–Co–Zn alloy system is stable in a very wide composition range, and conducted magnetization measurements, and X-ray and neutron diffraction experiments. We confirmed that the β -CoZn and the β - Mn 24 Co 36 Zn 40 alloys show a typical ferromagnetism with the Curie temperatures being 460 and 201 K, respectively. It is determined by Rietveld analysis for neutron data that the 8c site is entirely occupied by Co atoms, the 12d site by Zn and the remaining Co atoms, and the magnetic moment μ = 1.35 μ B /Co atom for the former alloy, and the 8c site is entirely occupied by Co and Mn atoms, the 12d site by Zn and the remaining Mn atoms, and the average magnetic moment μ = 0.76 μ B /(Mn or Co) atom for the latter alloy. The more Mn rich β - Mn 42 Co 28 Zn 30 alloy shows a micto-magnetic behavior, and has no long range magnetic order.

A rare all-Mn 2+ decametallic cage from distorted face-sharing cubes

The preparation and crystal structure of a decametallic Mn II carboxylate cluster containing neutral 2-pyridinealdoxime, (py)C(H)NOH, and its anion, (py)C(H)NO −, is reported. The reaction between Mn(O 2CPh) 2 · 2H 2O and (py)C(H)NOH in CH 2Cl 2, in the presence of NH 4PF 6, produces the complex [Mn 10(O 2CPh) 12{(py)C(H)CNO} 6{(py)C(H)NOH} 2](PF 6) 2 · 2.6CH 2Cl 2 · 1.3H 2O ( 1 · 2.6CH 2Cl 2 · 1.3H 2O) in good yield. The cationic complex consists of ten Mn II ions assembled together by four η 1:η 1:η 3:μ 4 and two η 1:η 1:η 2:μ 3 oximato(−1) ligands, and four η 1:η 2:μ 3 PhCO 2 - ligands to form an unprecedented { Mn II 10 ( μ -OR ) 4 ( μ - OR ′ ) 2 ( μ 3 - OR ′ ) 4 } 10 + core, where R = PhCO and R′ = (py)C(H)N. Peripheral ligation is provided by a combination of bridging benzoates and chelating (py)C(H)NOH ligands. Dc magnetic susceptibility studies reveal the presence of dominant antiferromagnetic interactions leading to a spin ground-state of S T = 0. A survey of the ternary Mn II / RCO 2 - / ( py ) C ( H ) NOH reaction system is attempted with comparisons to previously reported complexes.

Electrochemical and XPS studies of sputter-deposited ternary Mn–Ta–Cr alloys in chloride-free and chloride-containing sulphuric acid solutions

Amorphous manganese-rich (67–80 at.%) Mn–Ta–Cr alloy films were prepared by DC magnetron sputtering method. The corrosion behavior and stability of the Mn–Ta–Cr alloy films were examined in chloride-free and -containing 1 M H 2SO 4. AC and DC electrochemical techniques in combination with XPS analysis were used. Mn–Ta–Cr alloys exhibited very high corrosion resistance and stability up to transpassive dissolution region of chromium. The high corrosion resistance of Mn–Ta–Cr sputtered films is based on the formation of double oxyhydroxide passive film composed mainly of chromium and tantalum. The partial substitution of tantalum with chromium improves the corrosion resistance of the sputter-deposited alloys via accelerating the preferential dissolution of manganese and stabilizing alloy/passive film interface. A change in the passive film structure was observed when the alloys were anodically polarized at potentials higher than 0.6 V (SCE).

Corrosion-resistant MnZrCr alloys in chloride-containing media

Abstract New series of nanocrystalline and amorphous single phase binary MnZr and MnCr and ternary MnZrCr manganese-base alloys are successfully prepared by DC magnetron sputtering. Electrochemical measurements in combination with XPS analysis are used for examining the effect of single and binary additions of zirconium and chromium metals on the passivity and breakdown of manganese-base alloys in borate–boric acid solutions of pH 8.4 containing 0.01–1 M NaCl. Significant improvement in the resistance to passivity breakdown is observed when chromium and zirconium are added simultaneously to manganese instead of single addition of zirconium or chromium metals. The beneficial effect of simultaneous addition of zirconium and chromium is based mainly on the synergistic interaction between chromium and zirconium cations in the homogeneous double oxyhydroxide passive films formed on the alloy by open circuit immersion.

Preparation and characterization of spinel-type Mn-Ni-Co-O negative temperature coefficient ceramic thermistors

Powders of ternary Mn–Ni–Co oxide negative temperature coefficient thermistors were synthesized by a low-temperature alternative route. The procedure allowed straightforward preparation without the addition of any binder, of highly densified Mn–Ni–Co–O semiconducting ceramics as cubic single-phase spinels, at relatively moderate temperature (≈1000 °C). A tentative cation distribution for the Mn1.5Ni0.6Co0.9O4 spinel oxide has been proposed, and its variation with temperature has also been considered. The dilatometric and X-ray powder diffraction studies carried out for Mn1.5Ni0.6Co0.9O4 showed that sintering takes place in a single stage between 900 and 1000 °C, and yields highly densified ceramic with an apparant density larger than 96% of the calculated X-ray density. Scanning electron microscopy showed different microstructures for the Mn1.5Ni0.6Co0.9O4 spinel oxide, depending on sintering conditions. The value of the sensitivity index, β=3068 K, indicates a good technological thermistor performance for this material. © 1998 Chapman & Hall

Response to three-point bending of the forged L12 compound Al66Ti25Cr9

Abstract Several recent reports on the mechanical behavior of polycrystalline L1 2 trialuminides, particularly those based on the ternary AlTiCr and AlTiMn systems, have indicated limited tensile ductility at low temperatures (≤ 623 K) as measured in uniaxial tension or in three- and four-point bending. While plastic elongation in bending and in uniaxial tension was not observed for forged Al 66 Ti 25 Cr 9 at and below 473 K, some room temperature ductility was reported in bending for this compound in the cast and HIPed as well as in the extruded and annealed conditions. This study attempts to understand this discrepancy by subjecting the forged compound to a variety of heat treatments that influences the residual dislocation content and the grain size, and then evaluating bend specimens at 473 K. After identifying the heat treatment that provided the maximum ductility, a second set of bend specimens was heat treated and tested at 473 K as a function of strain rate (crosshead speed). Next, blocks of the forged material that had been suitably heat treated to maximize the 473 K bend ductility, were prestrained in compression (3 and 10%) at 298 and 1273 K. Bend specimens were obtained from these deformed blocks and tested at 473 K. The remaining material from the deformed block was heat treated to relieve the prestrain and retested in bending at 473 K. All bend tests were conducted in air. Bend specimens that were optimally heat treated were also tested at 473 K at a slow strain rate in diffusion pump oil to isolate the possible role of environment on ductility. Accompanying microstructures were characterized using optical and transmission electron microscopy and correlated with the measured properties.

Synthese und Struktur saurer Ubergangsmetallsulfate - Ti(H5O2)(SO4)2(H2O)2 und Zr(H3O)2(SO4)3 / Synthesis and Structure of Acid Transition Metal Sulfates - Ti(H5O2)(SO4)2(H2O)2 und Zr(H3O)2(SO4)3

Abstract From the ternary system Mn(SO4)n/2 / SO3 / H2O (Mn+ = Zr4+, Ti3+) two new acid metal sulfates, Ti(H5O2)(SO4)2(H2O)2 and Zr(H3O) 2(SO4)3, have been synthesized and structurally characterized. Ti(H5O2)(SO4)2(H2O)2 crystallizes in the orthorhombic space group Pnma with cell parameters a = 9.858(5), b = 18.32(2), c = 5.437(7)Å (Z = 4); Zr(H3O)2(SO4)3 crystallizes in the triclinic space group P1 with cell parameters a = 5.092(2), b = 8.533(3), c = 12.388(6)A, α = 92.95(3)°, β = 90.89(3)°, γ = 94.35(3)° (Z= 2). In the titanium compound there are slightly distorted TiO6 octahedra with Ti-O distances between 1.99 and 2.09 Å which are sharing corners with SO4 tetrahedra. Through hydrogen bonds layers are formed perpendicular to the b-axis. These layers are connected by H3O+ ions only. The structure of Zr(H3O)2(SO4)3 consists of three different SO4 tetrahedra and distorted ZrO7 polyhedra which are connected via common corners and edges to form columns parallel to the a-axis. The Zr-O distances vary from 2.13 to 2.18Å for equatorial positions, significantly longer than the axial Zr-O distances with 2.05Å.

Thermal analysis in the ternary NdMnSn system

Thermal analysis in the ternary NdMnSn system