Determination Of Phase Composition Research Articles

Impact of pH Preparation on the Physical Nature and Metal Phase of Zeolite-Supported Metal Catalyst

The synthesis of CoMo/USY catalysts has been widely carried out. However, the bond strength between metal and USY is still a problem. Therefore, this research has synthesised the catalyst with the chelating agent ethylenediaminetetraacetate (EDTA). Apart from that, the effect of pH on the characteristics of the catalyst is also reviewed. This research aims to analyse the effect of preparation pH on catalyst characteristics. In the preparation process, the pH of the solution is set at values of 2, 7, and 8. Catalyst activation includes a calcination process and reduction. The catalyst characterisation uses XRD, GSA, and FTIR instruments to determine phase composition, specific surface area, and functional groups. The result showed that pH preparation significantly influenced the metal loading on the catalyst and reached a maximum at pH 8. The surface area is not directly related to the pH of the preparation but has the opposite property depending on the amount of metal added. Meanwhile, it was found that the CoO and MoO3 phases were achieved on the catalyst by all pH preparations. On the other hand, the CoMo alloys are present on the catalyst at pH 7 and 8, while the Co and Mo elements are visible at pH 2. The difference in pH during the synthesis process impacts the shift in the absorption wave number of the OH vibration.

Study of The Effect of Calcination Temperature on the Phase Composition of ZnO Powder Synthesized via The Sol-Gel Method

This study investigated the effect of calcination temperature on the phase composition and crystal size of zinc oxide powders synthesised by the sol-gel method. Zn powder, HCl and NaOH were used as precursors in a multi-step process involving dissolution, titration, gel formation, leaching, drying and calcination at temperatures ranging from 300°C to 700°C for 2 hours. Rietveld analysis of X-ray diffraction (XRD) data using MAUD and Rietica software determined phase composition and crystal size. Initial analysis identified a single simonkolleite phase (Zn5(OH)8Cl2) prior to calcination, which disappeared at 500°C. Wurtzite (ZnO) appeared at 300°C, accompanied by secondary phases (NaCl and ZnCl2). The wurtzite content increased to 81.42 wt% at 700°C. Calcination temperature also influenced crystal size, which ranged from 27.34 nm to 110.61 nm for wurtzite at different temperatures. The results highlight the dynamic changes in phase composition and crystal size with different calcination temperatures, providing valuable insights into tailoring zinc oxide properties for various applications.

Synthesis of a Molybdenum-Containing Mo2C/C Composite Material with Functionalized Carbon Nanotubes

The Mo2C/C composite material was synthesized by the sol-gel method using molybdenum blue dispersions. Carbon nanotubes treated with HCl (acid treatment) and a mixture of H2SO4 and HNO3 (liquid-phase oxidation) were used as the carbon support. Samples of finished supports and composites were characterized by X-ray phase analysis, transmission electron microscopy, infrared spectroscopy, and low temperature nitrogen adsorption to determine phase composition, surface morphology, and porous parameters. It was established that the content of molybdenum carbide in a composite material is affected by the electrical surface properties of carbon nanotubes and molybdenum blue nanoparticles.

In Situ X-ray Diffraction as a Basic Tool to Study Oxide and Metal Oxide Catalysts

X-ray diffraction (XRD) is a standard technique that is widely applied in heterogeneous catalysis to determine phase composition, atomic structure, and size of crystallites. This review is focused on the application of in situ XRD for studying the catalysts during their “lifetime” (under synthesis, activation, operation, and deactivation conditions), limiting the objects of research to oxide and metal oxide catalysts. Also included is a brief overview of modern techniques and instruments and the latest works illustrating different aspects of this technique in catalyst research. The main conclusion is that the field of heterogeneous catalysis research would benefit substantially from the application of in situ XRD for the structural, phase, and morphological characterization of solid catalysts. Even more useful information can be obtained if XRD is combined with other techniques that are more sensitive at length scales different from that of XRD.

Tuning the activity of cobalt 2-hydroxyphosphonoacetates-derived electrocatalysts for water splitting and oxygen reduction: Insights into the local order by pair distribution function analysis

Pyrophosphate- or phosphide-based iron/cobalt electrocatalysts were prepared from the metal (R,S)−2-hydroxyphosphonoacetates to evaluate the effects of metal composition, N-doping and P-enrichment on the electrocatalytic activity. Rietveld and Pair Distribution Function analysis were used to determine phase composition. Irrespectively of the amorphous or crystalline nature, all pyrolyzed solids transformed under OER operation into biphasic Fe/CoO(OH), composed of discrete clusters (size ≤ 20 Å). Carbon paper-supported Fe0.2Co0.8O(OH) electrocatalysts displayed the best OER performances (overpotentials of 270–279 mV at 10 mA·cm−2), attributable to the formation of highly active bimetallic intermediate species. For HER, increased concentration of o-CoP in phosphide-based electrocatalysts resulted in improved performance, up to an overpotential of 140 mV. Employed as anode in alkaline water splitting, amorphous Fe-doped cobalt pyrophosphate and phosphide-derived electrocatalysts showed a cell voltage of 1.58 V at 10 mA·cm−2, with comparable stability to that of RuO2 and requiring lower voltage demand at high current densities.

Structural and thermal characteristics of Ti6Al4V (Ti64) metal powders for direct energy deposition

Ti6Al4V metal powder has been widely utilized in direct energy deposition (DED) of additive manufacturing (AM) technology, especially in aerospace applications. However, to secure excellent weldability between metal powder and substrate requires a proper understanding of heat-dissipation energy/created, especially when involving two components/materials with different thermal coefficients or properties. Therefore, an attempt is made in this work to investigate the structural and thermal characteristics of powder metals, including precursor powders such as Ti, Al, V, Al-V, and commercial established powder of Ti6Al4V (Ti64), respectively. Qualitative and quantitative analyses were employed accordingly to determine phase composition via X-ray diffraction (XRD) analyses. While phase stability, such as the thermal reaction and transition (ΔH) of these powders, was evaluated using differential scanning calorimetry (DSC). These findings are essential, especially in determining the reaction mechanism involved in various applications such as deposition process, mechanical alloying, and reaction sintering under a controlled environment. These fundamental characteristics are essential in producing high purity Ti64 metal powders and improve the weldability of the metal joining.

The Usefulness of X-ray Diffraction and Thermal Analysis to Study Dietary Supplements Containing Iron.

X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer’s claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form.

Research of physical and chemical processes associated with corrosion of cements (“Caking”) in dampy wet air

Objective. The paper is aimed at clarifying the mechanism and kinetics of the processes leading to cement caking. Methods. To determine phase composition, the following modern physical and chemical methods were used: XRF, derivatography and electron microscopy. Results. The data obtained show that the “aging” of cements during their forced storage in humid air through the adsorption of water vapor, and then CO2, is associated with the processes of hydrolysis, hydration in surface layers of particles, is primarily relevant for the most reactive minerals of Portland cement clinker. The deepening of these processes also depends on the state of the corroded surface of minerals. Conclusion. The work carried out makes it is possible to preliminarily outline storage conditions for freshly ground Portland cements (according to the kinetics of sorption – the storage duration, according to isotherms – the permissible relative humidity), at which the LOI value of commercial cement remains stable for the required minimum time.

Synthesis and characterization of different binary and ternary phase mixtures of mesoporous nanocrystalline titanium dioxide

Different phase compositions of mesoporous nanocrystalline TiO2 (meso-nc-TiO2), comprised of anatase (16–100%), rutile (0–70%) and brookite (0–52%) were obtained by sol–gel synthesis with or without hydrothermal treatment (HTT) by means of titanium tetrabutoxide and dibenzo-18-croun-6 as structure-forming agent in the presence of HCl. It was shown, that small amounts of surfactant and/or lanthanum salt as well as HTT determine phase composition and texture of meso-nc-TiO2. All samples were calcined at 500 оС and characterized by SEM, TEM, XRD and N2-adsorption/desorption isotherms. It has been established that photocatalytic properties of almost all obtained samples significantly exceed the photocatalytic activity of Evonik P-25 TiO2 in gas phase ethanol oxidation. The most active sample is characterized by phase composition of anatase (97%)-rutile (3%). It is obvious, that decrease of photocatalytic activity of sample was affected by decrease of anatase phase content. It was shown that the specific surface area of the sample is not a key factor affecting the activity of mixed-phase meso-nc-TiO2 samples in the process of ethanol oxidation.

Nickel and Cobalt Phosphides Fabricated through a Codeposition-Annealing Technique As Low-Cost Electrocatalytic Layers for Efficient Hydrogen Evolution Reaction

In the perspective of sustainable development, future economy will be increasingly dominated by carbon-free and renewable energy sources. In this context, hydrogen will play a fundamental role in the energy transition from fossil to green sources. Hydrogen can be easily produced employing water electrolysis, stored in large amounts and subsequently re-electrified in fuel cells. It offers the possibility to smooth the intermittency typical of many renewable energy sources and it constitutes an ideal complement for batteries in the transport sector. Efficient water electrolysis, however, makes use of noble metal electrocatalysts to lower the overpotential required for the Hydrogen Evolution Reaction (HER) to take place. Due to the limited availability and consequent high cost of noble metals, research is currently focusing on the development of low-cost alternative catalytic materials. One of the most studied electrocatalytic compounds are transition metal phosphides [1]. These materials present remarkable advantages over commonly used Pt based catalysts: lower cost, high abundancy and ease of manufacturing. In many cases, phosphides offer performances comparable to the noble metal electrocatalysts.In the present work, transition metal phosphides were fabricated through a simple and costless codeposition-annealing process. Amorphous Ni-P and Co-P alloys were codeposited with red phosphorus particles and subsequently annealed. The annealing step was applied to promote the formation of intermetallics and the interdiffusion between pure phosphorus particles and the metallic matrix. As a result, different phase pure metal phosphides were obtained. The most important advantage of this methodology is the possibility to overcome the compositional limit typical of electrodeposited phosphorus-based alloys [2]. Elemental phosphorus codeposition allows to reach P concentrations higher than 50 % at., whereas simple Ni-P solid solution electrodeposition is compositionally limited to 25 % at. Enhancing P content is fundamental to obtain phosphorus rich compounds like Ni2P and Co2P, which are characterized by high catalytic activities for HER [3]. Another interesting benefit of the technique presented is the confinement of elemental P inside the coating during the annealing step. This peculiarity strongly optimizes material usage and it limits the presence of gaseous phosphorus, which is typical of many phosphorization processes used in literature to obtain metal phosphides [4] and it can result into the formation of the unstable white P allotrope.Specifically, Ni-P and Co-P were codeposited with red P particles and process conditions were optimized to maximize elemental P particles concentration. Annealing temperature and duration were varied to investigate their influence on final electrocatalytic perfrormances. Characterization techniques like XRD, SEM, EDS, cross-sectional analysis and XPS were used to determine phase composition of the materials obtained and to characterize their morphology. The electrocatalytic HER activity and stability of the different transition metal phosphides were tested in 0.5 M H2SO4. In all the cases, remarkable results were obtained, which matched up well with present existing literature where similar electrocatalysts have been fabricated through different methods [5]. The lowest overpotential was obtained in the case of Co-P/P codeposition and subsequent annealing at 290 °C: 62 mV vs. RHE at a current density of 10 mA/cm2 in 0.5 M H2SO4 solution.[1] P. Xiao et al., Adv. Energy Mater. 5, 1500985 (2015)[2] R. L. Zeller and U. Landau, J. Electrochem. Soc. 139(12), 3464 (1992)[3] A. R. J. Kucernak et al., J. Mater. Chem. A 2, 17435 (2014)[4] X. Wang et al., Angew. Chem. 54(28), 8188 (2015)[5] Z. Pu et al., Chem.Mater. 26(15), 4326 (2014)

A comparison of the microstructures, thermal and mechanical properties of pressed and sintered Ti–Cu, Ti–Ni and Ti–Cu–Ni alloys intended for dental applications

The effect of Ni and Cu on the α→β phase transformation temperature, possible retention of the β-phase, and mechanical properties of Ti, Ti–13Cu, Ti–4.5Ni and Ti–13Cu–4.5Ni (compositions in wt. %) alloys were investigated. The alloys were developed using the conventional uniaxial cold press and sintering technique. The thermal properties of the sintered alloys were traced by the differential scanning calorimetry (DSC) analysis. The x-ray diffraction (XRD) and electron backscatter diffraction (EBSD) analysis determined phase composition, crystal structures and grain orientations. It has emerged that the Ti–13Cu and Ti–13Cu–4.5Ni retained the β-Ti phase. The mechanical properties were evaluated under tension with Ti–13Cu and Ti–4.5Ni possessing high ultimate tensile strength (UTS) and percentage elongation (%El) than the Ti–13Cu-4.5Ni alloy. Although all the alloys have revealed the presence of porosity, its effect on mechanical properties was more on the Ti–13Cu–4.5Ni alloy. While the mechanical properties of Ti–13Cu-4.5Ni alloy were inferior due to extensive porosity, those of Ti, Ti–13Cu and Ti–4.5Ni allow them to be classified as Type 3 and Type 4 dental alloys, respectively, proving that the conventional powder metallurgy process has potential to be used as a processing technique for Ti–Cu-based dental alloys.

Analysis of Phase Composition and CSR Sizes in Non-Equilibrium Nanostructured Systems Fe-Co and Ni-Cu Using Diffraction Maxima Simulations in a Doublet Radiation

The paper addresses the problem of determining phase composition, composition of mixed phases, and the CSR size in structurally similar metal systems where the most part of similar reflections of two phases overlap with each other. The overall experimental diffraction profile of overlapping reflections is decomposed into components by simulation techniques. The profile of each individual reflection is calculated as the convolution of the broadening function (in the form of the Pearson VII distribution with refined parameters) and an instrumental doublet function that is measured on a reference substance with a sufficiently large CSR size, shifted by an appropriate angle, and adapted to this position. As a result, parameters of profile components were identified and further used to determine phase compositions and compositions of mixed phases in nonequilibrium systems Fe-Co and Ni-Cu as well as the dependence of the CSR size on system’s composition.

Cornell’s Role in Developing Synchrotron Radiation for Mineral Physics

The newly invented diamond anvil cell (DAC) in 1960, and the newly constructed Cornell High Energy Synchrotron Source (CHESS) in 1979 were a perfect match, as CHESS could provide such an intense X-ray beam with such extraordinary properties that a whole new approach to mineral physics research became possible. The very high intensity of the X-ray beam from CHESS made it possible to make real-time observations of crystal structures during phase transitions for the first time. For instance, the olivine-spinel transition, important for understanding deep focus earthquakes can be shown to take place first by the displacive shift of oxygen layers supporting shear stress as most likely earthquake trigger followed by the diffusion of the cations to their positions in the spinel structure. X-ray emission spectra of high-pressure, high-temperature samples also made it possible to determine phase compositions, as well as the structures of complex ions in solution.

Effect of Micro SiC Addition on the Microstructure and Thermal Shock Resistance of 3D Printed Mullite Contained Ceramics

Currently, mullite contained ceramics printed by DIW 3D printing cannot be used in a high temperature environment for multicycle. In the fields of environmental protection and filtration of high-temperature flue gas, 3D printed mullite contained ceramics is in widely demanded owing to the variety of structures. Thus, application of these products have been limited due to their low thermal shock resistance. In order to improve the thermal shock resistance of 3D printed mullite contained ceramics for high-temperature flue gas filter, in this work, the effect of SiC micron particles addition on the thermal shock resistance was investigated. The thermal shock behavior of 3D printed mullite ceramics was explored using a conventional water quenching technique. Furthermore, XRD and SEM were used for determining phase composition and microstructure evaluation, respectively.

Transition Metal Phosphides Fabricated through a Codeposition-Annealing Technique As Electrocatalysts for Hydrogen Evolution Reaction

In the present work, transition metal phosphides were fabricated through a facile codeposition-annealing process. Pure red phosphorous particles were electrolytically codeposited with amorphous phosphorus containing alloys of general structure Me-P (with Me being a transition metal). A subsequent annealing step was applied to promote the formation of intermetallics and the interdiffusion between pure phosphorus particles and the metallic matrix. The main advantage of this approach is the possibility to easily obtain metal phosphides characterized by a very high P content, well beyond the limit typical of normal electrochemical processes involving induced codeposition of P [1, 2]. Another interesting benefit of the technique presented is the confinement of elemental P inside the coating during the annealing step. This strongly limits the presence of gaseous phosphorus, which is typical of different phosphorization processes used in literature to obtain metal phosphides [3]. Avoiding gaseous P is advantageous, since in specific conditions the formation of the highly dangerous white allotrope can take place. The use of P particles confined inside the coating is preferable also to phosphorization methods involving phosphine, an extremely poisonous gas commonly employed at lab level. The codeposition-annealing route described in the present work can be in principle applied to a number of transition metals for many different applications. One of the most attractive application for metal phosphides, however, is electrocatalysis for water splitting [4]. In this context, the codeposition-annealing technique was applied to the fabrication of Ni and Co phosphides, which can be used as catalytic substrates for Hydrogen Evolution Reaction (HER). These two materials present remarkable advantages over commonly used Pt based catalysts: lower cost, comparable performances and ease of manufacturing. Operatively, amorphous Ni-P and Co-P alloys were codeposited with P particles and subsequently annealed. As a result, different phase pure metal phosphides like Ni2P, Ni12P5, Co2P, Cu3P etc. were obtained after annealing. Characterization techniques like XRD, SEM (EDS), cross-sectional analysis and XPS were used to determine phase composition of the materials obtained and to characterize their morphology. Effect of annealing temperature and duration on phase composition were investigated as well. The electrocatalytic HER activity and stability of the different transition metal phosphides were tested in 0.5 M H2SO4. In all the cases, remarkable results were obtained, which matched up well with present existing literature where similar electrocatalysts have been fabricated through different methods [5]. For example, a Co2P electrocatalyst plated on copper and annealed at 290 °C exhibited excellent electrocatalytic activity for HER, showing a low overpotential of 62 mV at a current density of 10 mA/cm2 in 0.5M H2SO4 solution. [1] R. L. Zeller and U. Landau; J. Electrochem. Soc. 139 (12), 3464-3469 (1992) [2] A. Brenner; Electrodeposition of Alloys: Principles and Practice, Elsevier (2013) [3] X. Wang et al.; Angew. Chem. 54 (28), 8188-8192 (2015) [4] P. Xiao et al.; Adv. Energy Mater. 5 (24), 1500985 (2015) [5] Z.Pu et al.; Chem.Mater. 26 (15), 4326-4329 (2014)

Organo-Modified Vermiculite: Preparation, Characterization, and Sorption of Arsenic Compounds

Among the various technologies tested for removing the anionic species resulting from arsenic contamination, sorption methods have received unflagging interest. Being potential sorbent materials, clay minerals modified by cationic surfactants are often examined for this purpose. Among the clay minerals tested, information regarding sorption properties of expanded vermiculite modified with surfactants is scarce. Therefore, the present study aims to prepare organo-vermiculites modified with hexadecyltrimethylammonium (HDTMA) and benzyldimethylhexadecylammonium (HDBA) at surfactant concentrations of 0.5, 1.0, and 2.0 cation exchange capacity. Modified sorbents were identified and characterized using the analytical methods that can determine phase composition and textural properties of the samples. The sorption of As(III) and As(V) as a function of initial pH value, initial concentration of As(III, V), and initial dosage of sorbent was investigated. The results show that HDTMA and HDBA affect the properties of raw vermiculite. For instance, increase in the concentration of surfactants is often accompanied by a change in interlayer space or textural properties of vermiculite. It was observed that tested organo-minerals adsorbed As(V) to a greater extent compared to As(III). Various analytical studies were carried out and the results revealed the successful synthesis of organo-vermiculite. Moreover, the study also showed that the structure of organo-vermiculite has a significant impact on the uptake of As(III) and As(V) anions.

Studies of phase transitions occurring in the system of nanocrystalline Fe/NH3/H2

Nitriding of the iron catalyst and reduction of the obtained nitrides have been studied. Rate measurements of the reactions were conducted under atmospheric pressure and at 350 °C using a differential tubular reactor equipped with both a system to perform thermogravimetric measurements, to determine content of nitrogen in a solid phase, and a catharometric system to determine content of hydrogen in a gas phase. Mixtures of ammonia and hydrogen of a composition changing in a controlled way, were let into the reactor. Accelerations of the nitriding potential change were also varied. Ex-situ X-ray diffraction method was used to determine phase composition and mean nanocrystallites size of the solid sample. It was shown that in the ε-FeN0.33 iron nitride reduction there was a two-stage transformation. First, ε-nanocrystallites transformed into γ′ iron nitride in the order from the largest to the smallest. After complete transformation, γ′-nanocrystallites converted into the solution of nitrogen in nanocrystalline α-iron. In the reduction of nitrogen solution in ε iron nitride, ε-FeN0.48, however, there were simultaneously two mechanisms: a part of nanocrystallites of nitrogen solution in ε iron nitride underwent the two-stage transformation, while the rest underwent a one-stage transformation directly from the nitrogen solution in ε iron nitride to α-iron.

Synthesis and characterization of BaTiO3/\u03b1-Fe2O3 core/shell structure

Multiferroic materials attracted a lot of attention in recent years because of their significant scientific interest and technological applications. The multiferroic core/shell powders have a better connectivity between the phases, resulting in superior dielectric and magneto electric properties. In this study, the influence of preparation condition on structure and properties of BaTiO3/α-Fe2O3 core/shell composite materials was examined. The five samples were obtained by varying synthesis conditions, such as synthesized method (co-precipitation and sonochemical method) and pH values of solution. XRD and Raman spectroscopy analyses were performed in order to determine phase composition and structural changes within samples. Morphology modifications were examined by SEM and EDS analyses. Finally, effect of structural and microstructural changes on magnetic and electrical properties was detected and explained.

ELECTROMAGNETIC SHIELDING EFFECTIVENESS OF GYPSUM-MAGNETITE COMPOSITE AT X-BAND FREQUENCY

Rapid development of the electronic industry has increased the frequency of communication devices which lead to higher intensity of electromagnetic (EM) wave production. Too much exposure of EM wave can cause harm to health besides imposing disturbances in performances of other electronic devices. Hence, this research studies the structural and electromagnetic properties of materials that can act as electromagnetic shielding material at x-band frequency. Different compositions of magnetite powder/Fe3O4 (0, 10, 20 and 100 wt.%) were prepared to be dispersed in gypsum powders to form gypsum-magnetite composites. The structural properties of composites were characterized using Scanning Electron Microscopy (SEM) to observe homogeneity of the composites. The X-Ray Diffraction (XRD) was used to determine phase composition of the gypsum-magnetite composites. Scattering parameters of reflection coefficient, S11, and transmission coefficient, S21, were measured using Vector Network Analyzer (VNA). These parameters will be used to calculate the shielding effectiveness (SE) of gypsum-magnetite composite at x-band frequency. The results show that the total SE of the gypsum-magnetite composites were increased by adding magnetite powders.

Experimental study of the Be-C phase diagram

The phase equilibria in the Be-C system were studied via experiment technique. Eleven key alloys were prepared by powder metallurgy method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential thermal analysis (DTA) were used to determine phase compositions and phase transition temperatures. For the first time, the entire phase diagram for the Be-C system was obtained in the present work. The present work confirms that there is only one intermediate compound Be2C in this system. One allotropic transformation ((βBe) ↔ (αBe)) and two eutectic reactions (L ↔ (βBe) + Be2C and L ↔ Be2C + (C)) were determined.