Effect Of Mn Substitution Research Articles

Effect of Mn substitution on crystal structure and cyclic property of Y–Ni alloy with superlattice structure

This study investigated the crystal structure, P–C isotherm, and cyclic properties of YNi3. We discovered that hydrogen-induced amorphization (HIA) was appeared in three cycles of P–C isotherm at 303 K, but it was not observed at 273 K. An analysis of the three cycles at 303 K revealed a 55 % decrease in hydrogen capacity as compared to the first cycle. To enhance the hydrogenation properties, Mn was substituted for Ni. X-ray Rietveld refinements on YNi2·7Mn0·3H3.8 reveal that the hydride phase retains the PuNi3-type structure of the original alloy. The values of a, c, the unit cell, the MgZn2-type cell, and the CaCu5-type cell expanded 5.6 %, 9.3 %, 21.9 %, 25.0 %, and 18.8 % from the original alloy. The results indicated that YNi2·7Mn0.3 retained 91 % of its initial hydrogen capacity after three cycles at 303 K. After 120 cycles in the cyclic test, YNi3 and YNi2·7Mn0.3 retained 42 % and 90 % of their initial capacity, respectively. The XRD profile of YNi3 after 120 absorption-desorption cycles revealed significant peak broadening. Similarly, peak broadening was also observed in the XRD profile of YNi2·8Mn0.2 after 120 cycles. In comparison, the XRD profile of YNi2·7Mn0.3 after 120 cycles remained relatively unchanged from its initial state. It was observed that YNi2·7Mn0.3 experienced less lattice strain during hydrogenation than YNi2·8Mn0.2.

Effect of Mn substitution on Parasitic Reactions at the Interface of MgCr2-xMnxO4 Cathodes for Rechargeable Magnesium-Ion Battery

Effect of Mn substitution on Parasitic Reactions at the Interface of MgCr2-xMnxO4 Cathodes for Rechargeable Magnesium-Ion Battery

Study the Effect of Mn-Substitution on the Structural, Magnetic, and Dielectric Properties of Ba0.75Sr0.25Ti1−xMnxO3 Ceramics

Study the Effect of Mn-Substitution on the Structural, Magnetic, and Dielectric Properties of Ba0.75Sr0.25Ti1−xMnxO3 Ceramics

Effect of “Mn” substitution at B-site, on the crystal structure and energy storage performance of the La0.75Sr0.25CoO3 perovskite

This study explores the potential of redox-active electrode materials to address challenges in high-energy–density batteries and supercapacitor devices, including limited cyclic stability, slow charge storage kinetics, and low electrical conductivity. The investigation focuses on perovskite oxide-based electrodes, known for their compositional flexibility and structural stability, as a promising solution. Lanthanum-based perovskites, synthesized via the sol–gel combustion method, underwent comprehensive analysis, varying manganese (Mn) content from 0.25 to 0.75. Through X-ray diffraction, Rietveld analysis, scanning and transmission electron microscopy, energy dispersive X-ray analysis, and galvanometric potentiostat techniques, the effects of Mn-substitution at the B-site on structural, morphological, electron densities, and electrochemical behavior were thoroughly examined. La0.75Sr0.25Co0.5Mn0.5O3 (LCM-2) emerged as a stable variant with low internal strains, exhibiting the highest specific capacity (713C/g at a 2 mV/s scan rate) among all perovskite samples. Notably, LCM-2 perovskite displayed low electron density, which is attributed to oxygen deficiency, indicating its potential for application in highly energy-dense electrochemical energy storage devices. This research contributes valuable insights for advancing the development and commercialization of efficient energy storage technologies.

Effect of Mn substitution on the microstructure of (MgCoNiZnCu)O powder and its electrochemical performance as an anode material

Effect of Mn substitution on the microstructure of (MgCoNiZnCu)O powder and its electrochemical performance as an anode material

Effect of Mn substitution on Cr in the Al-Cu-Er-Mg-Zr-Fe-Si-Ti cast alloy

The microstructure, phase composition, precipitates evaluation, casting, and mechanical properties of the novel cast Al-4Cu-2.1Er-1Mg-0.2Zr-0.2Cr-0.15Fe-0.15Si-0.1Ti alloy were analyzed using by optical microscope, scanning and transmission electron microscopes, differential scanning calorimetry, thermodynamic calculations, hot cracking and mechanical properties measurements. The positive effect of Cr as a substitution of Mn on plasticity and precipitation strengthening was demonstrated. The 0.2Zr, 0.2Cr and 0.1 Ti as a grain refiners provide a fine grain size of 25 μm in the as-cast state due to primary Al75–80Cu10–12Er3–4Cr7 phase particles formation as a nucleation centers of Al. The hot cracking index (HCI) of the AlCuErMgCr alloy was 12–14 mm which is similar with HCI of the cast Al-Si-Cu-Mg alloys. The good casting properties in the AlCuErMgCr alloy achieved due to a fine grain structure and narrow solidification range. The contribution of the Al3(Zr,Er) (40 nm), Al45Cr7 (6 nm), and S’(θ’) (100/5 nm) precipitates is 38.5 MPa, 140.4 MPa, and 198.9 MPa and the calculated contribution from dislocation and precipitates is 262.3 MPa. The ultimate tensile strength (UTS) and elongation (El.) of the AlCuErMgCr alloy are 372 MPa and 6% which is higher in 16.6% and 150%, respectively, than in the Mn-containing alloy. Novel alloy has an excellent combination of yield strength (YS) and plasticity at 20–250°C. The YS and El. are 301 MPa and 6% and 225–250 MPa and 4.6–11.5% at 20 and 200–250°C, respectively. The rupture strength at 250°C after 100 h (σ100250) is 106 MPa. Mechanical and casting properties of the novel alloy are superior to the properties of commercial 201.0 (Al-Cu-Mn-Mg-Ag-Ti) alloy.

Effect of Mn Substitution on GeFe2O4 as an Anode for Sodium Ion Batteries

GeFe2O4 (GFO), with its intriguing intercalation mechanism based on alloying–conversion reactions, was recently proposed as an anode material for sodium ion batteries (SIBs). However, drawbacks related to excessive volume expansion during intercalation/deintercalation and poor electronic conductivity enormously hinder its practical application in batteries. In this regard, some experimental strategies such as cation substitutions and proper architectures/carbon coatings can be adopted. In this paper, pure and Mn-doped GFO samples were prepared by hydrothermal synthesis. The doped samples maintained the spinel cubic structure and the morphology of pure GFO. The electrochemical tests of the samples, performed after proper carbon coating, showed the expected redox processes involving both Ge and Fe ions. The Mn doping had a positive effect on the capacity values at a low current density (about 350 mAh/g at C/5 for the Mn 5% doping in comparison to 300 mAh/g for the pure sample). Concerning the cycling stability, the doped samples were able to provide 129 mAh/g (Mn 10%) and 150 mAh/g (Mn 5%) at C/10 after 60 cycles.

Sol-gel Synthesis of Mn-substituted Copper Ferrite Nano Particles as Anode for Lithium Ion Batteries

Mn substituted copper ferrites (MnxCu1-xFe2O4, x = 0, 0.33, 0.67, 1.00) have been synthesized from metal nitrates and citric acid by sol-gel method (chemical process). This study aims to know the effects of Mn substitution on structural, magnetic, and electrochemical properties of copper ferrites. For characterizing the prepared ferrites, different techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were used. In addition, vibrating sample magnetometer (VSM) is used to investigate the magnetic properties such as saturation magnetization (Ms), residual magnetism (Mr) and coercive force (Hc). A single-phase spinal structure was confirmed by XRD and lattice parameter was increased from 8.36 Å to 8.52 Å with increasing Mn contents. Micrographs of SEM shows that nanoparticles are agglomerated and non-uniform in size. The FTIR analysis shows that theses absorption band about 1422 cm-1 to 1434 cm-1 was attributed octahedral B-site. For pure copper ferrite, band is shifted towards higher frequency by manganese content. The results from CV showed that the increasing in scan rate and specific capacitance decreases due to increase in the area loop which clearly means that the investigated samples are best for storage devices such as lithium ion batteries (LIBs).

DFT insights into LaFeO3 with Mn substitution: A promising path to energy-efficient magneto-optical applications.

In recent years, the demand for electronic materials has significantly increased, driven by industrial needs and the pursuit of cost-efficient alternatives. This comprehensive study investigates the effects of Mn substitution on LaFeO3 through the implementation of the GGA approach in density functional theory. The research findings demonstrate remarkable consistency with the experimental outcomes reported in the existing literature pertaining to the studied compounds. However, this study unveils novel insights into the mechanical and optical characteristics of the doped structures, which have not been previously reported. The structural stability is rigorously examined through multiple stability criteria, encompassing structural optimization, tests of elastic stability, and enthalpy of formation calculations. Furthermore, the electronic and optical properties of the compounds exhibit exceptional improvements in conductivity and reflectivity as a result of the doping process. The band structure analysis reveals the presence of a Moss-Burstein shift. Investigation of the magnetic properties indicates an increase in the magnetic moment value due to the Fe-Mn degeneracy resulting from increased Mn content. Mechanical analysis of the elastic moduli B, G, and Y demonstrates an enhanced strength and metal-like conductivity, attributed to the induced anharmonicity. Moreover, the internal strain factor suggests a higher degree of bond flexibility, implying potential applications of these compounds in flexible electronics.

Effect of Manganese-Doping on the chemical and optical properties of cobalt ferrite nanoparticles

We report on the effect of manganese (Mn) doping on the structural, chemical and optical properties of cobalt ferrite (CFO) nanoparticles (NPs). The Mn(II)-substituted CFO NPs with variable chemical composition (Co1-xMnxFe2O4; x = 0.0–0.5; CMFO) were synthesized by an eco-friendly hydrothermal route. The CMFO NPs produced were with a crystallite size varying in the range of 8–14 nm, where the chemical valence state, chemical bonding, electronic structure and optical properties are strongly influenced by the Mn-substitution. The X-ray diffraction (XRD) studies revealed the Mn-substitution induced changes in CFO crystal structure. The Mn-substitution in CFO causes the lattice parameter enhancement (a), crystallite size increase, and micro-strain (ε) as evident in the XRD studies. The chemical composition driven direct, functional relationship reflected in a-D-ε correlation, which suggests the Mn-substitution allows the ability to control the size and strain in CFMO NPs. Chemical bonding analyses using Fourier transform infrared spectroscopy (FTIR) corroborates with structural assessment made with XRD studies. The MTd–O (MTd = metal ions in tetrahedral locations) absorption bands shifting to higher wavenumbers in FTIR studies indicate that, Mn-substitution induce changes in the metal cation distribution between the tetrahedral and octahedral locations of the ferrite lattice. The X-ray photoelectron spectroscopic (XPS) analyses indicate the presence of iron as Fe+3, cobalt as Co+2, and manganese in Mn+2 chemical state. With increasing Mn-content, the XPS revealed that the binding energy (BE) separation of Fe, as well as Mn, does not change compared to Co, indicating the chemical stability and valence state of Fe+3 and Mn+2 cations maintained well in the CMFO samples. While the overall chemistry of CFO is maintained, and is not influenced by the increasing Mn-concentration, the remarkable effect of Mn-substitution is seen on the optical properties of CFO NPs. The optical studies indicate that the band gap of CFO NPs exhibits a direct, functional dependence on Mn-concentration; the band gap varies in a wide range of 2.38–3.12 eV. The analyses indicate the exponential dependence of CFO optical band gap with Mn-content which provide a roadmap to engineer the materials with tunable band gap for desired technological applications.

Effect of Mn substitution on the electronic structure for Mn-doped indium-tin oxide films studied by soft and hard x-ray photoemission spectroscopy

Effect of Mn substitution on the electronic structure for Mn-doped indium-tin oxide films studied by soft and hard x-ray photoemission spectroscopy

Effect of moderate Fe doping and heat treatment on the microstructure of Ni-Mn-Ga melt-spun ribbons

The present work investigates the effects of Mn substitution with additions of Fe (0.5, 1, 2, and 3 at%) on the crystal structure, phase transformation temperatures, and magnetic properties of casted and heat-treated Ni49.8Mn28.5−xGa21.7Fex magnetic shape memory (MSM) alloys. The alloys doped with 0.5 and 1 at% Fe exhibited single-phase seven-layered modulated (14 M) and five-layered modulated (10 M) martensite structures at ambient temperature, whereas the alloys doped with 2 and 3 at% Fe exhibited L21 Heusler austenite structures at ambient temperature. The Ni49.8Mn27.5Ga21.7Fe1 alloy exhibiting the 10 M crystal structure at ambient temperature was selected for making ribbons using the melt-spinning process. The effects of heat treatment on grain growth, crystal structure, and other functional properties of the melt-spun ribbons were studied. The ribbons heat-treated at 1273 K exhibited a 10 M martensite structure and an average grain size of 220 µm along the ribbon plane. The results show that Ni49.8Mn27.5Ga21.7Fe1 is a particularly promising composition for designing and manufacturing functional MSM micro-actuators.

Effect of Mn Substitution on the Dielectric Constant and Breakdown Voltage of Anti-ferroelectric PLZT

Effect of Mn Substitution on the Dielectric Constant and Breakdown Voltage of Anti-ferroelectric PLZT

Structural effects of Mn-substitution in β-FeSe

In the present work the structural and microstructural properties of Mn substituted β-FeSe are inspected by using high-resolution synchrotron X-ray powder diffraction data collected between 10 K and 150 K. It is demonstrated that the thermal increase of the structural strain in the tetragonal phase progressively breaks the 4-fold symmetry at the local scale, qualitatively tracing the development of anisotropy measured in some physical properties, generally ascribed to nematicity. This result points to a close relationship and interplay between structural strain and physical properties; with this notion, the structural strain can be considered as the origin of the unexpected anisotropy observed in some physical properties. Remarkably, incommensurate satellite peaks are observed in the diffraction pattern collected in the low-temperature orthorhombic phase field, likely related to the occurrence of a charge-density-wave instability.

Effects of Mn-substitution on magnetic properties of R6TX2-based (R = Gd–Dy, T = Mn–Ni; X = Sb and Te) multinary compounds

The multinary compounds Dy6Mn0.3Fe0.7Sb2, Dy6MnSbTe, {Gd, Tb}6FeSbTe, Gd3Tb3FeSbTe, {Gd, Tb}2Dy4Mn0.25Fe0.75Sb2, Gd2Tb4Mn0.25Fe0.75SbTe, Tb6Mn0.25{Fe, Co, Ni}0.75SbTe, Tb6Mn0.4Co0.6SbTe and Tb6Mn0.5Ni0.5SbTe crystallize in the Zr6CoAl2-type structure (ordered variant of the Fe2P structure) (space group P-62m, N 189, hP9). The polycrystalline samples Gd3Tb3FeSbTe, {Gd, Tb}2Dy4Mn0.25Fe0.75Sb2, Gd2Tb4Mn0.25Fe0.75SbTe, Tb6Mn0.25{Fe, Co, Ni}0.75SbTe, Tb6Mn0.4Co0.6SbTe and Tb6Mn0.5Ni0.5SbTe exhibit high-temperature ferromagnetic ordering and low-temperature field sensitive transformation of magnetic ordering. Of these compounds, Gd2Tb4Mn0.25Fe0.75SbTe shows the highest Curie temperature at 292 K with the low-temperature transformation of magnetic ordering at 60 K. Gd3Tb3FeSbTe displays the strongest hard magnetic properties at low temperatures with residual magnetization per formula unit of 16 μB and coercive field of 16 kOe at 2 K. Tb6Mn0.25Ni0.75SbTe and Tb6Mn0.4Co0.6SbTe exhibit large magnetocaloric effect with magnetic entropy change of −4.6 J/kg⋅K and −4.5 J/kg⋅K, respectively, around Curie temperature in a field change of 50 kOe.The specific features of Mn-catalysis/substitution for magnetic properties of these compounds are viewed and discussed.

Effect of Mn substitution on plateau pressure regulation of the Ti0.92Zr0.1Cr1.6−xMnxFe0.4 alloys for primary hydrogen compressor

The Ti0.92Zr0.1Cr1.6−xMnxFe0.4 (x = 0.15, 0.3, 0.45, 0.6 at%) alloys were synthesized by vacuum electric arc furnace. The effect of Mn substitution on plateau pressure regulation of these alloys was investigated for the primary hydrogen compressor. With increasing Mn content, the hydrogen absorption/desorption plateau pressures of the Ti0.92Zr0.1Cr1.6−xMnxFe0.4 (x = 0.15, 0.3,0.45,0.6 at%) alloys increased, the plateau slope factor decreased, meanwhile, both enthalpy and entropy change values decreased. The Ti0.92Zr0.1Cr1.0Mn0.6Fe0.4 alloy had the best comprehensive performance. Based on the pressure composition isotherms measurement, the plateau pressure and hydrogen storage capacity were obtained at 298–363 K. The hydrogen absorption/desorption curves of the Ti0.92Zr0.1Cr1.0Mn0.6Fe0.4 alloy at 353 and 363 K were firstly tested by experiment method. At 298 K, the hydrogen absorption plateau pressure and maximum capacity were 7.82 MPa and 1.79 wt%. At 363 K, the hydrogen desorption plateau pressure and maximum capacity were 27.21 MPa and 1.54 wt%. Hydrogen pressure from 8 MPa to 25 MPa was successfully obtained at 298–363 K, satisfying operating temperature and pressure requirements for the primary hydrogen compression materials.

First principles calculation to investigate the effect of Mn substitution on Cu site in CeCu3-x Mn x V4O12 (x = 0, 1, 2 and 3) system.

Structural, electronic, elastic and magnetic properties of CeCu3-x Mn x V4O12 (x = 0, 1, 2 and 3) system have been carried out through DFT using GGA, GGA+U and HF potential. The investigation of structural optimization reveals that lattice parameters of the understudy system is reliable with the reported results and are increasing with the Mn substitution due to their greater atomic radii as compare to Cu atom. Both the cohesive energy and the enthalpy show that CeCu3V4O12 is the most thermodynamically stable among these compounds. When Mn is replaced by Cu in these compounds, not only it become semi-metals, but the host compound also changes from non-magnetic to anti-ferromagnetic and their electrical resistance provides further credence to their electronic behavior. Mechanical stability, anisotropy, and ductility are all demonstrated through the elastic characteristics of these compounds. Due to anti-ferromagnetic ductile nature of the Mn base compounds, it is expected that the compounds in the system may use for spintronic application and in magnetic cloaking devices.

UV–vis-enhanced photothermal catalytic reforming of biomass model tar via LaMnxNi1-xO3 perovskite catalyst

Tar formation during biomass gasification reduces energy efficiency and poses a negative impact on downstream applications. A photothermal steam reforming (PTR) system based on LaMnxNi1-xO3 (0 ≤ x ≤ 1) perovskite was developed to convert tar into combustible gas. The effects of Mn substitution, temperature, and the steam to carbon ratio on PTR activity were investigated. Mn substitution increased the content of surface adsorbed oxygen and maintained the perovskite structure of LaMn0.4Ni0.6O3 (LM4N6). Moreover, LM4N6 showed improved optical absorption and electron-hole separation properties. LM4N6 presented 90 % carbon conversion during PTR at 400 °C. Due to the introduction of ultraviolet–visible light (UV–vis), LM4N6 obtained better catalytic activity and stability in PTR than in the thermal catalytic reforming process. Detailed characterization and experiments proved that UV–vis effectively activated Ni sites and the oxygen species on LM4N6 and formed a photothermal synergistic effect, which inhibited carbon deposition and improved catalytic activity and stability. This work provides a novel concept for the conversion and utilization of biomass tar at low temperatures.

Effects of the on-site energy on the electronic response of Sr3(Ir1−xMnx)2O7

We investigated the doping and temperature evolutions of the optical response of Sr3(Ir1−xMnx)2O7 single crystals with 0 ≤ x ≤ 0.36 by utilizing infrared spectroscopy. Substitution of 3d transition metal Mn ions into Sr3Ir2O7 is expected to induce an insulator-to-metal transition via the decrease in the magnitude of the spin–orbit coupling and the hole doping. In sharp contrast, our data reveal the resilience of the spin–orbit coupling and the incoherent character of the charge transport. Upon Mn substitution, an incoherent in-gap excitation at about 0.25 eV appeared with the decrease in the strength of the optical transitions between the effective total angular momentum Jeff bands of the Ir ions. The resonance energies of the optical transitions between the Jeff bands which are directly proportional to the magnitude of the spin–orbit coupling hardly varied. In addition to these evolutions of the low-energy response, Mn substitution led to the emergence of a distinct high-energy optical excitation at about 1.2 eV which is larger than the resonance energies of the optical transitions between the Jeff bands. This observation indicates that the Mn 3d states are located away from the Ir 5d states in energy and that the large difference in the on-site energies of the transition metal ions is responsible for the incoherent charge transport and the robustness of the spin–orbit coupling. The effect of Mn substitution was also registered in the temperature dependence of the electronic response. The anomaly in the optical response of the parent compound observed at the antiferromagnetic transition temperature is notably suppressed in the Mn-doped compounds despite the persistence of the long-range antiferromagnetic ordering. The suppression of the spin-charge coupling could be related to charge disproportionation of the Ir ions.

The effects of Mn substitution on the crystalline phase structure, microstructure, DC resistivity, and magnetic-dielectric properties of Z-type hexaferrites

A series of the Ba1.5Sr1.5Co2-xMnxFe23O41 (x = 0.0–0.5) hexaferrites was prepared by the conventional solid-state reaction method. The crystalline phase structure, microstructure and magneto-dielectric properties of samples were investigated. Z-type and W-type phases were detected in hexaferrites sintered at 1200 °C. Mn substitution can reduce the content of the second phase, changes the ion occupancy, magnetic moment, and electron hopping in hexaferrite. Therefore, the magnetic, DC resistivity, and dielectric properties were altered, and the losses were successfully reduced in the substituted samples. Particularly, the Ba1.5Sr1.5Co1.8Mn0.2Fe23O41 hexaferrite has a more homogeneous crystal phase; its μi is 18.5, fr exceeds 1 GHz, and the Snoek’s constant reaches 18.55 GHz. At the same time, this hexaferrite were characterized by a relatively large magnetic quality factor and low dielectric losses (tanδε<0.05 below 500 MHz). This Z-type hexaferrite has excellent high-frequency magneto-dielectric properties and holds a potential for use in miniature antennas.