Binary Mn Research Articles

A crumpled sphere-like NiMn metal-organic phosphate as electrode material for electrochemical supercapacitor

The present study investigates a crumpled sphere-like binary Ni Mn metal–organic phosphate (Ni10Mn1-MOPh) sample for its potential application in electrochemical supercapacitors. Additionally, control samples of NixMny-MOPhs with varying proportions of Ni and Mn were also prepared. It is noteworthy that NixMny-MOPh samples with different molar ratios of Ni:Mn display different morphologies and electrochemical supercapacitor properties. Compared with other as-prepared NixMny-MOPhs, Ni10Mn1-MOPh modified electrode showed more complete sphere, bigger active surface area, and faster electrical conduction, applying for the hydrothermal condition is pivotal factor for the practical applications of NixMny-MOPhs. The synthesized Ni10Mn1-MOPh demonstrates a remarkable specific capacitance value of 986.8F/g at 2 A/g and exhibits exceptional reversible charge/discharge capability with an approximate retention rate of 81.9 % after 5000 cycles at 6 A/g. As a proof-of-concept, we synthesized bare Ni-MOPh and MnO2, thereby further confirming that the optimization electrochemical performance is associated with the synergistic effect of diverse active metals, their respective ratios, and the appropriate morphology of the NiMn-MOPh samples.

Nanoscale chemical and structural investigation of solid solution polyelemental transition metal oxide nanoparticles

Although it has been shown that configurational entropy can improve the structural stability in transition metal oxides (TMOs), little is known about the oxidation state of transition metals under random mixing of alloys. Such information is essential in understanding the chemical reactivity and properties of TMOs stabilized by configurational entropy. Herein, utilizing electron energy loss spectroscopy (EELS) technique in an aberration-corrected scanning transmission electron microscope (STEM), we systematically studied the oxidation state of binary (Mn,Fe)3O4, ternary (Mn, Fe, Ni)3O4, and quinary (Mn, Fe, Ni, Cu, Zn)3O4 solid solution polyelemental transition metal oxides (SSP-TMOs) nanoparticles. Our findings show that the random mixing of multiple elements in the form of solid solution phase not only promotes the entropy stabilization but also results in stable oxidation state in transition metals spanning from binary to quinary transition metal oxide nanoparticles.

Single-phase Mn-Fe interfacial oxides nanocomposites encored on carbon nitride sheets exhibited enhanced performance for electrocatalytic oxygen reduction reactions

• Precious-metal-free cathode catalyst for sustainable energy application developed. • Interfacial binary oxides share single-phase geometry constituting cathode catalyst. • Mn-Fe oxides with carbon nitride synergistically enhanced electrocatalytic ORR. • Developed catalyst exhibited two folds higher ORR activity than commercial Pt/C. The oxygen reduction reactions (ORR) catalysis in fuel cells plays a pivotal role to complete the reactions at the cathode side. The economical low-cost of catalyst is highly required for competing for commercial catalysts with enhanced performance. Herein, we have been successful in developing precious-metal-free catalyst with characteristic features of single-phase interfacial binary Mn and Fe oxides on carbon nitride (Mn-Fe-O/CN) composite material. The performed physical characterizations such as TEM, HRTEM, XRD, Raman and XPS revealed and confirmed the synthesis of the composite material in line with the claimed features. The developed catalyst was tested for oxygen reduction reactions in an acidic medium, and the compared performance with that of commercial 20% wt Pt/C catalyst exhibited enhanced ORR performance with an onset potential of 0.84V vs RHE, which is comparable to that of Pt/C. In addition, the Mn-Fe-O/CN catalyst generated two folds higher current density calculated at 0.90V vs RHE compared with the Pt/C catalyst. The enhanced ORR performance of Mn-Fe-O/CN catalyst may ascribe to the multi-features of composite material, which boosted the simultaneous adsorptions and chemisorptions of oxygen molecules at interfacial binary oxide surface due to electrons transference phenomenon supported by metal-to-support interactions of graphitic carbon nitride intimated sheets.

Dolomite-derived composites doped with binary ions for direct solar thermal conversion and stabilized thermochemical energy storage

Thermochemical energy storage (TCES) via the calcium looping (CaL) process is an emerging technology applied in third-generation concentrated solar power plants. A range of CaO-based composites was developed via binary Fe and Mn ions doping of low-cost dolomite for direct solar absorption. The doping ratio of Fe and Mn ions was investigated and optimized aiming to produce the highly efficient Fe/Mn-doped, acid-modified dolomite composites. After comprehensively considering the spectral absorptance and energy storage density, the composite with a molar ratio of Ca/Mg:Mn:Fe=100:2:4 is optimal. It possesses a relatively high spectral absorptance of 63.7% due to the generated, dark Ca-Mn-Fe oxides, which is up to ∼2.1 times higher than that of raw dolomite. Moreover, the composite exhibits excellent cycling stability (a gravimetric energy storage density loss of ∼6.6% after 30 cycles) resulting from uniformly distributed, intrinsic MgO grains. Additionally, dolomite-derived composite pellets were prepared using extrusion-spheronization, and their volumetric energy density is remarkably superior to that of the powder, ∼2.37 GJ/m3 after 30 cycles. The fresh pellets (7.25± 0.64 MPa) and calcined pellets (3.19 ± 0.29 MPa) both possess desirable ability to resist mechanical stress and thermal shock. Therefore, Fe/Mn-doped, dolomite-derived composite pellets are potential candidates for direct solar absorption when applied in CaL-based TCES systems due to their simultaneously desirable spectral absorbance and cycling stability.

Control in Local Coordination Environment Boosting Activating Molecular Oxygen with an Atomically Dispersed Binary Mn–Co Catalyst

Activation of molecular oxygen plays a crucial role in natural organisms and the modern chemical industry. Herein, we report a Mn-Co dual-single-atom catalyst that exerts a specific synergy in boosting O2 activation by collaboration between two distinct types of activation sites. Taking the oxidative esterification of the biomass platform 5-hydroxymethylfurfural (HMF) as the model reaction, the activation of O2 is demonstrated through transforming O2 into a reactive superoxide anion radical (O2•-) on Co-N4 sites and, meanwhile, by reversible consumption and supplement of coordinated surface oxygen as a new type of reactive oxygen species (ROS) on N,O-coordinated single-atom Mn sites (Mn-NxOy). EXAFS analysis results show a longer average Mn-O bond distance at near 2.19 Å, which makes the breaking and formation of surface Mn-O bonds easier to cycle. Control experiments support that such Mn-O bonding conditions could facilitate H-elimination of C-H in HMF. The co-existence of two types of ROS effectively matches the oxidation of hydroxyl and aldehyde groups, and thus, the overall reaction is boosted in excellent yield of diester (95.8%) with an extremely high carbon balance. This study represents a rare example of taking advantage of the synergy of the diatomic catalyst for activating O2 by two types of activation pathways.

Metal ions-bridged J-aggregation mediated nanoassembly composition for breast cancer phototherapy

Recently, the highly ordered J-aggregates of organic dyes with intriguing optical properties have received considerable attention in biomedical applications. Herein, binary metal ions Mn(II)/Fe(III) are used to induce the formation of indocyanine green (ICG) J-aggregates. Further, the sheet-like J-aggregates are able to act as "carriers" for loading hydrophobic chemotherapeutic gambogic acid (GA), realizing the effect of "killing two birds with one stone" for both treatment and delivery. The as-designed nanoassembly is formed spontaneously in aqueous environment via π-π stacking, electrostatic interaction, and hydrophobic force, exhibiting enhanced photostability of ICG and outstanding reactive oxygen species (ROS) generation ability. Moreover, significant inhibition of tumor growth by the synergetic effect of phototherapy and chemotherapy is verified in a subcutaneous 4T1 tumors model. In conclusion, this work not only presents a facile and green approach to manufacture carrier-free nanodrugs, but also establishes a universal platform that has potential application in the co-delivery of near-infrared dye and hydrophobic molecules.

RETRACTED: Two new Mn(II) coordination polymers: Photocatalytic property and treatment activity on colorectal cancer by inhibiting cancer cell migration and invasion

Two new binary Mn(II) coordination polymers, namely [Mn(5-MeO-ip)(DMF)] n ( 1 ) and [Mn(obb)] n ( 2 ) (5-MeO-H 2 ip = 5-methoxyisophthalic acid, H 2 obb = 4,4′-oxydibenzoic acid), have been synthesized via the self-assemble reactions of Mn(II) ions with two different dicarboxylic acid ligands. The optical band gaps for 1 – 2 are 3.21 eV, 3.50 eV, respectively, and their photocatalytic properties for the degradation of MV under UV light irradiation were also investigated. For the colorectal cancer treatment, the biological activity was evaluated and the specific mechanism was explored at the same time. Firstly, the inhibitory activity of the new compounds on the colorectal cancer cell viability was measured with CCK-8 assay. Next, the real time RT-PCR was used to measure the activation of the VEGF signaling pathway in the colorectal cancer cells after compound treatment.

Insights into the underlying mechanisms of stability working for As(III) removal by Fe-Mn binary oxide as a highly efficient adsorbent

Fe-Mn binary oxide has received increasing interest in treating As(III)-containing polluted groundwater due to its low cost and environmental friendliness. Although the stability of Fe-Mn binary oxide is as important as its adsorption ability, little is known about whether and why Fe-Mn binary oxide is stable during As(III) removal. In this study, five successive cycles were conducted to evaluate the stability of Fe-Mn binary oxide for As(III) removal. As(III) oxidation/adsorption kinetics and the speciation distribution of the released Fe and Mn elements within single Fe oxide, Mn oxide, and Fe-Mn binary oxide were investigated by using characterization techniques of TEM-EDS mapping, selected area electron diffraction (SAED), and XPS combined with a binary component reactor, where Fe and Mn oxides were separated by a semipermeable membrane. The results revealed that Fe-Mn binary oxide could maintain excellent stability, although As(III) oxidation/adsorption behavior was coupled with the release of Fe and Mn ions from its surface. The great stability of Fe-Mn binary oxide for As(III) removal was attributed to the rapid return of aqueous Fe(II) and Mn(II) to the solid surface, which subsequently formed new mineral phases mediated by Fe and Mn oxides, thus considerably decreasing the loss of released Mn(II) and Fe(II).

The effect of Si addition and thermomechanical processing in an Fe-Mn alloy for biodegradable implants: Mechanical performance and degradation behavior

Among iron-based materials, the Fe-Mn system appears to be highly suitable for the development of biodegradable metals for orthopaedic and vascular applications. The versatility of tailoring such steels by alloying provides many opportunities to customise biodegradable devices. In the field of applications where a high load-bearing capacity is required, the addition of Si could constitute an effective strategy to improve the mechanical properties while maintaining a similar corrosion susceptibility and biocompatibility. In this study, the microstructure, mechanical properties, and corrosion behaviour of Fe-30 Mn-5Si (wt.%) alloy are presented, discussed, and assessed in comparison with a binary Fe-30 Mn formulation. Emphasis is placed on characterising the alloys in processed conditions by using conventional thermomechanical rolling and annealing techniques, which are feasible and allow for scale-up. Such techniques affect phases equilibrium, internal stresses and grain size, thus altering the degradation behaviour. The addition of Si resulted in excellent microstructural homogeneity and was used to tailor the relative abundances of austenitic and martensitic phases by applying different heat treatment strategies. As a result, the mechanical resistance was improved by 70 % compared to the base alloy, the strain hardening ability was improved while keeping good ductility. Electrochemical corrosion tests and static degradation experiments showed that both alloys corrode at a similar rate, although the addition of Si appeared to induce a slower degradation in the initial stage and a faster one in the long term.

Dual-metal-organic frameworks derived manganese and zinc oxides nanohybrids as high performance anodes for lithium-ion batteries

Metal-organic framework (MOF) derivatives are attracting increasing interests for next-generation lithium-ion battery anode materials. Here, a novel approach has been applied to synthesize binary Mn–Zn oxides nanohybrids embedded in porous carbon matrix by pyrolysis of dual-metal-organic frameworks. The as-fabricated MnO/ZnO@C nanohybrids exhibit superior lithium storage capabilities, reaching a reversible capacity of 1396 mAh g−1 at 0.2 A g−1 with an initial coulombic efficiency of higher than 75%. When cycled at 2 A g−1, the electrode maintained at 636 mAh g−1 after 1000 cycles, indicating the outstanding high-rate capability and cycling stability. The improved electrochemical performance can be attributed to the interconnected porous structure of carbon frameworks and uniform heterostructure nanohybrids, which efficiently improve the charge transfer and buffer the volume expansion during repeated lithiation process. These findings demonstrate an efficient strategy of using dual-MOF-derived bi-metal oxide nanostructures as high performance anodes for lithium-ion batteries.

Advanced thermal stability investigations of the Mn–Al-Ga system

A ternary Mn–Al-Ga alloy with the nominal composition Mn55Al38.57Ga6.43 was produced by arc melting. After homogenisation, the alloy consisted of the ε and γ2 phases. Appropriate heat treatments were used to transform each of these into a phase with the L10 structure. These two L10 phases had different compositions, lattice parameters and magnetic properties. In order to test the stability of the L10 phases against decomposition, heat treatments were carried out at 700 ​°C for durations of up to 14 days. The results showed that the decomposition started with formation of the β-Mn phase and subsequent appearance of the γ2 phase. The resulting diffusion gradients resulted in composition changes in the L10 phases and after 7 days, only a single, intermediate composition remained. After 14 days, the decomposition was almost complete. The decomposition of the L10 phases in the ternary Mn–Al-Ga alloy was significantly slower than in binary Mn–Al alloys.

An evaluation of the Mn–Ga system: Phase diagram, crystal structure, magnetism, and thermodynamic properties

The Ni–Mn-Ga alloy system is attractive due to its functional properties with potentials in various applications. However, the fundamental alloy thermodynamics of the binary Mn–Ga system is still lack of investigation. Therefore, a comprehensive evaluation of the Mn–Ga is performed in this work. Different versions of Mn–Ga phase diagrams available in the literature are reviewed. A new version of the Mn–Ga phase diagram is recommended along with possible invariant reactions. The crystal structure, magnetic transition, and thermochemical properties of intermetallic compounds are reviewed by considering available experimental and modeling such as ab initio calculations. In fact, more experimental information on the Mn-rich side is required in order to perform CALPHAD thermodynamic modeling for a reliable database. Further experiments are recommended to study the high-temperature phase equilibria between liquid, (γMn), (δMn) and Mn2Ga(h), phase reactions between Mn8Ga5 and Mn7Ga6, and invariant reactions involving the MnGa phase. Nevertheless, the summarized information on phase equilibria, phase diagram, crystallography, magnetic transition temperature, magnetic moment, heat capacity, and enthalpy of formation can support the future thermodynamic investigation of the Mn–Ga system, which is critical for the materials design and discovery of Ni–Mn-Ga alloys.

The influence of laser processing parameters on the densification and surface morphology of pure Fe and Fe-35Mn scaffolds produced by selective laser melting

Highly customisable implants with lattice structures can be achieved using selective laser melting (SLM) paving the way for tailored biodegradable Fe-based implants. For the first time, a systematic analysis is presented in terms of laser processing conditions required for scaffolds of pure Fe and a binary Fe-35 Mn alloy. The processability of the two materials were compared in terms of densification behaviour, surface roughness and geometrical error. Both materials were successfully processed into high quality scaffolds with excellent strut morphology and low processing porosity. The differences in the laser processing conditions between the pure metal and the binary alloy were discussed. The lower melting temperature of the Fe-35 Mn alloy required lower energy density for reaching the fully dense condition. Surface roughness and geometrical errors were found to be similar for the two materials. The microstructure of pure Fe was characterized by equiaxed α-ferrite grains, whereas the Fe-35 Mn had a microstructure consisting of columnar γ grains, with each γ-grain comprising of a network of individual cells.

Disorder in Mn+1AXn phases at the atomic scale

Atomic disordering in materials alters their physical and chemical properties and can subsequently affect their performance. In complex ceramic materials, it is a challenge to understand the nature of structural disordering, due to the difficulty of direct, atomic-scale experimental observations. Here we report the direct imaging of ion irradiation-induced antisite defects in Mn+1AXn phases using double CS-corrected scanning transmission electron microscopy and provide compelling evidence of order-to-disorder phase transformations, overturning the conventional view that irradiation causes phase decomposition to binary fcc-structured Mn+1Xn. With the formation of uniformly distributed cation antisite defects and the rearrangement of X anions, disordered solid solution γ-(Mn+1A)Xn phases are formed at low ion fluences, followed by gradual transitions to solid solution fcc-structured (Mn+1A)Xn phases. This study provides a comprehensive understanding of the order-to-disorder transformations in Mn+1AXn phases and proposes a method for the synthesis of new solid solution (Mn+1A)Xn phases by tailoring the disorder.

Binary Mn–Si nanostructures prepared by focused electron beam induced deposition from the precursor SiH3Mn(CO)5

Mixed-metal carbonyls are a family of compounds which can be used to fabricate bimetallic nanostructures by means of focused electron beam induced deposition. In the present work, we show that silicon-metal alloys can be prepared by using silyl-metal carbonyls. In particular, we employ the SiH3Mn(CO)5 precursor to fabricate Mn–Si alloy nanowires, with composition of about 34 at% Mn, 17 at% Si, 31 at% C and 18 at% O, as revealed by energy dispersive x-ray analysis. Magnetotransport measurements are carried out on as-grown samples and on samples treated after-growth by low-energy electron irradiation. All the samples exhibit a quasi-metallic temperature-dependent behavior. Hall-effect measurements indicate either electron-like transport, for as-grown samples, or hole-like transport, for post-growth treated samples, respectively. Correspondingly, the charge carrier density increases from cm−3 to cm−3. We find a small negative transversal magnetoresistance, which depends on irradiation dose and temperature. Microstructural investigations carried out by transmission electron microscopy indicate that the samples are constituted by an amorphous Mn2Si phase embedded in a carbonaceous matrix. Additionally, in treated samples a novel Mn2SiO4 spinel oxide phase is observed.

Enthalpies of mixing in binary Mn–In and ternary Mn–In–Gd liquid alloys

AbstractThe enthalpies of mixing in liquid alloys of the binary Mn–In and ternary Mn–In–Gd systems were determined over a wide range of compositions by means of isoperibolic calorimetry in the temperature range 1 500 – 1 650 K. The enthalpies of mixing in the Mn–In system demonstrate endothermic effects (ΔHmax = 4.66 ± 0.38 kJ · mol−1 at xIn = 0.40). The enthalpies of mixing in the liquid ternary Mn–In–Gd alloys were determined along six sections (xMn/xIn = 0.22/0.78; 0.44/0.56; 0.65/0.35 and 0.83/0.17 for xGd changed from 0 up to 0.5 and xMn/xGd = 0.30/0.70; 0.60/0.40 for xIn changed from 0 up to 0.3). Enthalpies of mixing in the ternary system were found to be predominantly exothermic and steadily increasing in absolute values towards the Gd–In boundary binary system, reaching the maximum value in the vicinity of the phase GdIn.

МОДЕЛЮВАННЯ ТЕРМОХІМІЧНИХ ВЛАСТИВОСТЕЙ ТА СХИЛЬНОСТІ ДО АМОРФІЗАЦІЇ РОЗПЛАВІВ ПОТРІЙНОЇ СИСТЕМИ Mn–Al–Gd

In the present work, the enthalpies of mixing of liquid alloys of the ternary Mn-Al-Gd system have been calculated using the regular solution model by the Redlich-Kister-Muggianu formula. Also a comparison was made of calculated values of enthalpies of mixing in this system with the experimentally determined thermochemical properties of liquid alloys of the Mn-In-Gd ternary system obtained previously. In general, we estimate that the values of the enthalpies of mixing in the Mn-Al-Gd ternary system should be more exothermic than in the Mn–In-Gd one. This fact can be explained taking into consideration the main features of the component interaction in the boundary binary systems, namely, such important characteristics as electronegativity of the components, their electron work functions and a large difference in size of atoms. It can be concluded that it is the binary Mn–Al system that makes a significant contribution to the formation energy of ternary alloys. An imaginary line drawn through the points of maximum curvature of the isoenthalpic lines is considerably shifted towards the binary Mn–Al boundary, thus expanding significantly the region of rather exothermic enthalpies of mixing in the corresponding ternary system. For the two indicated ternary systems the size mismatch entropy has been calculated within the framework of hard spheres model and the Sσ/kB parameter has been determined. On the basis of the comprehensive analysis carried out, the criteria for the probability of occurrence of regions of easy amorphization in these ternary systems are proposed. The determination of the topology of the mixing enthalpy surface and the Sσ/kB parameter for the melts of studied ternary systems together with the data on binary and ternary compounds existing in these systems allowed to reasonably assume the concentration regions where the investigated ternary alloys have tendency for easy amorphization while rapid cooling of the melt. The simultaneous realization of the following three conditions was taken as a criterion for the possible existence of a region of easy amorphization: the absolute value of the enthalpies of mixing is at least 6 kJ/mol, the Sσ/kB parameter is not less than 0.3–0.4 and a certain distance from the concentration region corresponding to the exact composition of binary or ternary compounds.

Photo-catalytic activity of highly efficient binary Mn–Fe nano composite oxides for degradation of cresol fast violet: phase formation and band gap study

Binary Mn–Fe nano composite oxides as highly efficient photo-catalyst was prepared and applied for photo-catalytic degradation of cresol fast violet. The binary Mn–Fe nano composite oxides were prepared by precipitation pyrolysis technique using nitrate precursors with calcination temperature of 400 °C. Phase formation and band gap properties of nano-particles in the course of the preparation method were studied by FTIR, XRD, EDX, FESEM and DRS analyses for conversion of Mn–Fe nitrates to binary Mn–Fe oxides. The XRD data revealed a rhombohedral iron oxide (hematite) and tetragonal manganese oxide MnO2 as nano composite without any impurity phases. The absorption peaks attained from 539 to 610 cm−1 in FTIR spectra for manganese dioxide are corresponded to the characteristic stretching collision of oxygen–manganese–oxygen, which confirmed the existence of the tetragonal manganese oxide. The characteristic absorption bands at 539 and 473 cm−1 are related to Fe–O stretching and bending vibration mode of α-Fe2O3 respectively. The broad band appeared at 473 cm−1 is due to the presence of Fe–O–Mn linkage in the binary Mn–Fe nano composite oxide. FESEM results showed that the surface morphology of the nano composite was regular shape agglomeration of grain-like particles with rough surface morphology with an average size of 23 nm which is also comparable with the size obtained by XRD data analysis. The value of band gap for binary Mn–Fe nano composite oxide was 1.66 eV with a red shift compared with α-Fe2O3 (2.3 eV) and MnO2 (2.41 eV) attributed to coupling of α-Fe2O3 with MnO2. The coupling between α-Fe2O3 with MnO2 with different band gaps to form heterojunctions in photocatalytic systems significantly enhanced the optical absorption of photocatalysts. The coupling between α-Fe2O3 with MnO2 can also effectly reduces the recombination rate of the photogenerated charge carriers. The photocatalytic activity of nano-composite showed maximum degradation of 95% for degradation of cresol fast violet dye solution using the binary Mn–Fe nano composite oxide photocatalyst coated on glass.

Binary Fe and Mn Oxide Nanoparticle Supported Polymeric Anion Exchanger for Arsenic Adsorption: Role of Oxides, Supported Materials, and Preparation Solvent

In this work, binary Fe/Mn oxide nanoparticles were incorporated onto the matrix of anion exchange resin, resulting in hybrid polymeric/inorganic nanoadsorbent named as A502P-Fe/Mn. During synthesis process, effects of various types of metal oxides, preparation solvent, supporting materials, and loading cycles were also investigated. To reduce the charge repulsion force between cationic Fe3+ and Mn4+ ions and fixed-positively charged quaternary amine (R4N+) functional groups of the anion exchange support, mixed solution containing DI/ethanol was introduced to dissolve metal salts during the preparation process. The data obtained by equilibrium batch test indicated that the A502P-Fe/Mn prepared from mixed 50:50 of DI and ethanol exhibited the highest As (V) sorption capacity. The synthesized material was further characterized by using scanning electron microscope (SEM) equipped with energy dispersive X ray spectroscopy (EDX) to verify the existence and distribution of elemental Fe, Mn, and As inside the polymeric beads. Equilibrium As (V) sorption isotherm, effect of solution pH, and point of zero charge of material were also evaluated. This A502P-Fe/Mn can have a promising potential for arsenic removal applications.

Predicting Pathways for Synthesis of Ferromagnetic τ Phase in Binary Heusler Alloy Al-55 pct Mn Through Understanding of the Kinetics of ε–τ Transformation

This paper outlines the detailed procedure for the synthesis of pure ferromagnetic tau phase in binary Heusler Al-55 pct Mn alloy in bulk form through casting route without any addition of stabilizers. To obtain the processing domain for the formation of the tau phase from high-temperature epsilon phase, isothermal transformation experiments were carried out. The structure and microstructure were characterized by X-ray diffraction and electron microscopy studies. The tau phase start times were obtained through magnetic measurements. In order to tune the casting conditions for the formation of this phase, thermal modeling was carried out to predict the heat extraction rates for copper molds of different diameters (2 to 12 mm) containing hot solids during casting process. This enabled us to estimate the diameter of the mold to be used for obtaining tau phase directly during casting. It was concluded through experimental verification that 10-mm-diameter casting in copper mold is suitable to obtain complete tau phase. A saturation magnetization of 116 emu/g at 10 K was measured for such samples. The Curie point for the tau phase was found to be 668 K (395 A degrees C). Additionally, the cast rod exhibits a compressive strength of 1170 MPa which is higher than those of both ferrites and AlNiCo magnets.