Sn Atoms Research Articles

Open Sn Framework Structure Hosting Bi Guest atoms – Synthesis, Crystal and Electronic Structure of Na13Sn26Bi

Although several Na‐Sn‐Pnictides with a variety of structural motives are known, no ternary compound in the Na‐Sn‐Bi system has been described yet. In this paper we present the Zintl‐phase Na13Sn25.73Bi1.27 comprising a complex, open‐framework structure of Sn atoms, with one mixed Sn/Bi site, hosting Na atoms. An additional Bi atom is loosely connected with only weak contacts to the framework filling a larger cavity within the network. According to band structure calculations of the two ordered variants with either full occupation of the mixed site with Sn or Bi, resulting in Na13Sn26Bi and Na13Sn24Bi3, respectively, both compounds are semiconductors with band gaps of 0.5 eV. A comparison of the band structures with the related binary compounds Na5Sn13 and Na7Sn12 shows that only the perfectly charge balanced Na7Sn12 is a semiconductor whereas Na5Sn13 is metallic. The rather specific electronic situation in the ternary compound is traced back to the loosely bound Bi atom, which acts as a guest atom according to Bix@Na13Sn27‐x‐yBiy, with x=1 and y=0.27, capable to change its oxidation state and thus to uptake additional electrons to form a semiconductor. Na13Sn25.73Bi1.27 is a rare example of an open framework structure of Sn atoms comprising Bi atoms in the cavities.

Growth mechanism, stability and electronic structures of Sn doped Cu clusters

Recently, the single-Sn-atom-doped Cu of Cu20Sn1 is reported (ACS Catal. 2021, 11, 11103−11108), which is selective to CO with a maximum faradic efficiency. However, the structure evolutions and electronic properties of Sn doped Cu clusters are not well established. Here, the growth patterns, stability and electronic structures of SnCun (n = 1-9) clusters are first analysed in detail. It is found that the structural transitions of them are found to occur at the SnCu3 and SnCu7, respectively, where the Sn atoms trend to stabilise at the vertex sites with high-coordination numbers. Among them, the tetragonal pyramidal SnCu4 has a higher stability than that of its neighbours and can maintain the structural integrity at 700 K. The molecular orbitals and density of states reveal that the SnCu4 has a 1S21P6 superatomic electronic shell, which is further confirmed by the density of states analysis. The electrostatic potential surfaces confirmed that the SnCun have significant σ-hole regions at the Cu atomic sites, except for SnCu and SnCu2. The charge analyses show that the direction of charge flows is from the Cun frameworks → Sn.

Trimetallic Alloys as an Electrocatalyst for Fuel Cells: The Case of Methyl Formate on Pt3Pd3Sn2.

The shift toward renewable energy sources plays a central role in the quest for a circular economy. In this context, methyl formate (MF) has garnered attention as a compelling hydrogen carrier and alternative fuel, because of its remarkable characteristics (energy density, ease of storage and transport, and low boiling point). In this study, DFT calculations supported by online electrochemical mass spectroscopy (OE-MS) were performed to investigate the MF electro-oxidation (MFEO) on Pt3Pd3Sn2 (111). The DFT calculations provide insight into the role of Pt, Pd, and Sn atoms in MFEO. Pt and Pd together provide a preferred active site for initiating MFEO through the O-H bond scission, and Sn plays an essential role in the mitigation of CO through oxygenation or water activation. By comparing the reaction energies and activation barriers for all possible reactions in MFEO, the suggested path necessitates a minimum energy of 0.14 eV to initiate the MFEO. This value was supported by the experimental results, showing that the oxidation wave of MF starts at 0.15 V (70 °C). Density functional theory (DFT) results, supported by OE-MS, indicate that the hydrolysis of MF prior to MFEO is not preferred on Pt3Pd3Sn2 (111) surfaces, although the formation of methanol is plausible via a CH3O intermediate. Among the three small organic molecules (SOMs) studied─MF, methanol, and formic acid─MF has the lowest activation energy for the initial bond breaking that starts the whole oxidation process (0.13 eV), compared to formic acid (0.45 eV) and methanol (0.61 eV); thus, MF is the preferred fuel on Pt3Pd3Sn2 (111).

Effect of Oxidized Tin Interfacial Atoms on Methylcyclohexane Dehydrogenation Catalyzed by γ‐Alumina Supported Platinum Clusters

AbstractTin (Sn) doped platinum (Pt) nanoparticles supported on γ‐alumina are important materials catalyzing various reactions, such as the dehydrogenation of methylcyclohexane (MCH) into toluene, involved in liquid organic hydrogen carriers process, and naphtha catalytic reforming. The role of oxidized forms of Sn, remains misunderstood. Relying on catalysts' models made of a Pt13cluster on the (100) surface of γ‐alumina, the location and effects of Sn4+and Sn2+ interfacial atoms are investigated by density functional theory (DFT) calculations. A simulated annealing approach based on ab initio molecular dynamics enables to explore the configurations of the catalytic systems. The Pt clusters' stabilities and that of the adsorbed molecular intermediates are linked to the electronic properties of the cluster and to its ductility modulated by the adsorbed species, the alumina support and the Sn atoms. The Gibbs free energy profiles related to the reaction mechanism of the MCH dehydrogenation into toluene are quantified on the basis of transition state search. The energy span concept reveals that the dual (either detrimental or beneficial) impact of Sn oxidized forms on the intrinsic reactivity of the Pt13 cluster depends on temperature. Based on this DFT analysis, we attempt to clarify the debated role of Sn oxidized species.

Sn-doped n-type GaN freestanding layer: Thermodynamic study and fabrication by halide vapor phase epitaxy

Results of a thermodynamic study of Sn doping and fabrication of a Sn-doped GaN freestanding layer with high structural quality by halide vapor phase epitaxy (HVPE) are described in this paper. Thermodynamic analysis revealed that SnCl2 and/or SnCl act as Sn precursors through the reaction between Sn metal and HCl gas. The equilibrium partial pressures of SnCl2 and SnCl increase with the input HCl partial pressure. To generate Sn precursors effectively, it is desirable that the reaction between Sn metal and HCl gas occurs in the inert gas ambient. On the basis of results of the thermodynamic study, the Sn-doped GaN freestanding layer with a Sn concentration of 5.7 × 1019 cm−3 is fabricated by removing the GaN seed substrate after HVPE growth. The Sn-doped GaN freestanding layer has high crystal quality, and the lattice constants along the c- and a-axes of the Sn-doped GaN freestanding layer are larger than those of the GaN seed substrate because of the high electron density and the size effect of Sn atoms.

Carbothermal Reduction-Assisted Synthesis of a Carbon-Supported Highly Dispersed PtSn Nanoalloy for the Oxygen Reduction Reaction.

Exploring high-performance and low-platinum-based electrocatalysts to accelerate the oxygen reduction reaction (ORR) at the air cathode of zinc-air batteries remains crucial. Herein, by combining electroless deposition and carbothermal reduction, a nitrogen-doped carbon-supported highly dispersed PtSn alloy nanocatalyst (PtSn/NC) was prepared for a high-efficiency ORR process. Electrochemical measurements show that PtSn/NC exhibits excellent electrocatalytic ORR activity with a half-wave potential of 0.850 V versus reversible hydrogen electrode (RHE), which is higher than that of commercial Pt/C (0.815 V). The PtSn/NC-based (20 μgPt cm-2) rechargeable Zn-air battery exhibited astonishing performance with a maximum power density of up to 150.1 mW cm-2, as well as excellent rate performance and charge/discharge stability. Physical characterization reveals that carbothermal reduction could compel the transformation of Sn oxide into metallic Sn, which then alloys with the deposited Pt atoms to form the PtSn nanoalloy, in which electrons are transferred from Sn atoms to neighboring Pt atoms, thereby improving the ability of Pt-based active sites to catalyze the ORR process in PtSn/NC by optimizing the unoccupied d-band of Pt atoms. This work provides a reliable and innovative route for the rational design of highly dispersed Pt-based alloy ORR electrocatalysts.

Revisiting the role of foreign atoms in [formula omitted] reduction on CuSn single-atom surface alloys

The electrochemical CO2 reduction is a promising process for capturing the emitted carbon dioxide by converting CO2 into value-added chemicals. Although copper-based catalysts have a unique ability to produce multi-carbon products, they suffer from poor selectivity. Copper-based alloys and, in particular, single atom alloys, hold promise for fine-tuning the selectivity of CO2 reduction reaction. In this study, we applied the grand canonical density functional theory in combination with the implicit solvent to model CO2 electroreduction with the formation of CO and HCOO− on copper and highly diluted copper-tin alloys. We demonstrate that the insertion of a substitutional Sn atom introduces a destabilization effect for all intermediates and completely disrupts the adsorption positions of the CO, H, and H/CO2 co-adsorption. However, the influence of Sn on intermediate adsorption energies is primarily localized in its immediate vicinity. We demonstrate that sparsely distributed single Sn atoms do not account for the experimentally observed significant reduction in formate and hydrogen generation across the entire Sn-substituted Cu surface. This discrepancy underscores the need to reevaluate the proposed surface structure and the nature of the active sites on CuSn single-atom surface alloys.

First principles insights into the electronic and magnetic properties of [formula omitted] doped with VIII-group transition metal single atom

Inspired by the unprecedented surface chemical reaction activity of single-atom catalysts (SAC), this research presents a theoretical study on the doping of SnO2(110) surface with transition metal group VIII atoms (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt). Using density functional theory (DFT), the formation energy, electronic structure, charge transfer, and magnetic moments of the SnO2(110) system before and after doping were investigated. The formation energies of the different doped systems vary depending on the doping position. The doping of transition metal (TM) atoms can induce produces both charge transfer and magnetic moment. The charge transfer is largest in the Pd-doped system, with + 0.68 e at the position of the penta-coordinated Sn atom (Sn5c position) and + 0.67 e at the position of the hexa-coordinated Sn atom (Sn6c position), while the Co-doped system exhibits the smallest charge transfer of + 0.19 e (Sn6c position). Fe, Co, Ni, Ru and Os atoms introduce magnetic moments, with the Fe-doped system (Sn5c position) having the highest magnetic moments of 2.91 μB. In the SnO2(110) surface system doped with TM atoms, there are varying degrees of orbital overlap between the TM atoms and their surrounding O atoms. This theoretical work provides valuable insights into the physical properties of metal oxide based single-atom catalysts.

Efficacy of Radical‐Scavenging Activity in Novel Diorganotin(IV) Complexes of Schiff Bases of Salicylaldehyde

AbstractBiopotent hybrid diorganotin(IV) complexes, derived from salicylaldehyde Schiff bases having general formula R2SnL, where LH = (OH)C6H4HC: NCR′(R″)CHR‴OH] [where R = Me or Bu], were logically designed, generated, and characterized using spectroscopic techniques, single‐crystal X‐ray investigations, and DFT studies. Different diorganotin(IV) complexes were synthesized because of interaction between diorganotin(IV) dichloride and sodium salts of Schiff bases of salicylaldehyde ligand in anhydrous refluxing THF at 1:1 and 1:2 molar ratio (Product A and B). The chelating property of Schiff bases replaces organo group from diorganotin(IV) dichloride. It creates an O2SnL type of complex when diorganotin(IV) dichloride and ligand interact in 1:2 ratio, which is this study's most fascinating aspect. The characterization of these complexes is aided by physicochemical and spectroscopic investigations, including IR and NMR (1H, 13C, and 119Sn). Single‐crystal X‐ray investigations, mass spectrum studies, and DFT investigations suggest the dimeric structure of these compounds. These diorganotin(IV) complexes have a dimeric structure containing hexacoordinated central tin atom. Two µ2─O atoms bridge the gap between two Sn(IV) atoms in the dimeric dimethyltin(IV) complexes. The DPPH assay results for radical scavenging activity and IC50 values demonstrate the antioxidative potential of diorganotin(IV).

Modification of the Spectral Absorption Characteristics of ZnGeP2 in the THz and IR Wavelength Ranges Due to Diffusion Doping with Impurity Atoms of Mg, Se, Sn, and Pb

This study demonstrates that diffusion doping of ZGP single crystals with impurity atoms (Mg, Se, Sn, Pb) leads to a decrease in the specific conductivity of the samples. Consequently, this results in reduced absorption in the terahertz frequency range (150–1000 μm). It has been shown that doping ZGP samples with selenium (Se) and lead (Pb) atoms reduces absorption in the infrared region from 0.3–0.6 cm−1 to 0.06–0.09 cm−1. Doping with tin (Sn) leads to a decrease in absorption only in the wavelength region near 2.1 μm from 0.2 cm−1 to 0.05 cm−1. The proposed mechanism for the decrease in infrared absorption is a reduction in zinc vacancies due to doping with impurity atoms. This research lays the groundwork for a technology that produces ZGP crystals with minimal absorption within the 2–8 μm wavelength range, eliminating the need for fast electron beam irradiation technology. This advancement will facilitate the fabrication of ZGP crystals with arbitrary apertures.

Construction of homogeneous electron collection center at buried interface based on triazine-based graphdiyne for efficient perovskite solar cells

The properties of the buried interface between electron transport layer (ETL) and perovskite is critical factors to influence the performance of conventional perovskite solar cells (PSCs). Herein, functionalized triazine-based graphdiyne (Tz-GDY) nanospheres are prepared and employed to build up electron collection center and optimize the SnO2/perovskite interface. The pyrazine ring with homogeneous N element distribution and alkyne bond of Tz-GDY can passivate the undercoordinated Sn to remodel the electron density distribution around the Sn atoms and thus effectively eliminate the trap defects and inhibit the recombination loss significantly. In addition, the as-prepared Tz-GDY based nanospheres uniformly distribute at the SnO2/perovskite interface and a larger grain and more uniform perovskite film is obtained due to the increased contact angle. Moreover, Tz-GDY nanospheres can reduce the fermi energy level to facilitate the electron injection. Consequently, the Tz-GDY modified PSCs exhibits a champion power conversion efficiency of 24.83 % with effectively suppressed hysteresis. Our strategy proposes a more efficient electron collection method in buried interface, providing a guidance for constructing efficient PSCs.

First-principles study of Na adsorption and diffusion over substitutionally doped antimonene

The storage of the colossal amount of energy is the eminent research area for the era of eternal need of energy. Sodium-ion (Na-ion) battery emerged as an appropriate alternative to fulfil this. Here, we investigate the functionalities of doped antimonene monolayer (with Ge, Se, Sn and Te atom) as an anode material for Na-ion battery using First-principles Density Functional Theory (DFT) approach. The adsorption and diffusion of Na over the substitutionally doped antimonene is well supported thermodynamically with an adsorption energy of range −2.3 eV to −2.8 eV and minimum activation energy of range 0.1 eV to –0.8 eV. The conductivity of doped antimonene increases with the number of Na atoms adsorbed over it as seen by bandstructure, density of states (DOS) and electron difference density (EDD) plots. Inhomogeneities and structural disturbances were absent during adsorption and diffusion indicating a robust electrode material. The outcomes predict that the doped antimonene monolayer can be a potential candidate for Na-ion battery anode material application.

Doped‐Sn Enhanced the Performance of BiOCl Nanosheet on Electrocatalytic Synthesis of Hydrogen Peroxide

AbstractThe hydrogen peroxide (H2O2) produced through electrochemical two‐electron oxygen reduction reaction (2e− ORR) is a promising green synthesis method and served as potential strategy to replace the energy‐intensive anthraquinone process. Nevertheless, the design of low‐cost and efficient electrocatalysts for 2e− ORR remains a formidable challenge. In this study, Sn‐BiOCl nanosheets electrocatalysts are prepared for expediting the 2e− ORR, achieving a high H2O2 selectivity of 92.9%, and the H2O2 yield of 10628 mg L−1 h−1 (0.1 mg cm−2) in a flow‐cell device. The in situ ATR‐SEIRAS results reveal that Sn‐BiOCl enhances the adsorption and activation of *OOH compared to BiOCl, resulting in higher activity and selectivity for 2e− ORR. Furthermore, this study investigates the potential for on‐site production and application of H2O2 using Sn‐BiOCl, which displays a 95% degradation removal of dyes (RhB, MB, and MO) within 20 min. This work not only have an insight into the critical roles of Bi and Sn atoms in enhancing the catalytic performance but also provides a thought to design efficient catalysts for production H2O2 via electrochemical 2e− ORR.

Modulated assembly and structural diversity of heterometallic Sn-Ti oxo clusters from inorganic tin precursors.

Through modulating the multidentate ligands, solvent environments, and inorganic tin precursors during the synthesis processes, we have successfully prepared a series of unprecedented heterometallic Sn-Ti oxo clusters with structural diversity and different physiochemical attributes. Initially, two Sn6Ti10 clusters were synthesized using trimethylolpropane as a structure-oriented ligand and SnCl4·5H2O as a tin source. Then, when a larger pentadentate ligand di(trimethylolpropane) was used instead of trimethylolpropane and aprotic acetonitrile solvent was introduced into the reaction system, four low-nuclearity Sn-Ti oxo clusters were discovered, including two Sn1Ti1, one Sn2Ti2 and one Sn2Ti6. Finally, two mixed-valence state clusters, SnII4SnIV2TiIV14 and SnII4SnIV4TiIV20, were obtained by transforming the tin precursor from SnCl4·5H2O to SnCl2·2H2O and adjusting the acetonitrile solution with trace acetic acid/formic acid. Sn8Ti20 is the highest-nuclearity heterometallic Sn-Ti oxo cluster to date. Moreover, comparative electrocatalytic CO2 reduction experiments were carried out, and it was concluded that the Sn8Ti20-decorated electrode showed the most satisfactory performance due to the influence of mixed-valence states of the Sn atoms and the charging effects provided by 20 Ti4+ ions. This study presents important guiding significance for the design, synthesis and application optimization of functional heterometallic nanoclusters.

Experimental subshell vacancies in a multiply ionised Sn atom by heavy ion impact

The adoption of Heavy Ion PIXE for elemental quantification remains limited by the lack of fundamental atomic parameters needed for the calculation of X-ray production cross section data. Widely adapted theoretical models used for approximating ionisation cross sections, as well as other atomic physical parameters such as X-ray fluorescence yields, are calculated based on single-hole vacancy production post ion-atom impact. This renders the use of conventional ‘protonic’ models invalid for heavy ion-atom collisions. The degree to which Multiple Ionisation (MI) manifests in different heavy ion-atom collision symmetries significantly modifies atomic physical parameters. This is due to the significant number of introduced spectator vacancies in higher subshells, especially where near-symmetry is approached and MI is more pronounced. Knowledge of the mean number of vacancies in upper subshells is thus important for modifying atomic parameters that are needed for the translation of ionisation to X-ray production cross sections. In the present study, MI effects for Sn L-shell X-rays were studied using characteristic X-ray energy shifts measured using a standard PIXE spectrometer induced by Si, Cu and I projectile ions with incident energies up to 0.75 MeV/u. MI satellite distributions were studied using a Wavelength dispersive X-ray spectrometer (WDS) for high resolution PIXE, induced by C and Si projectile ions with incident ion energies up to 1.25 MeV/u. The mean number of subshell vacancies in the M- and N- shell for energy shifted Sn Lα X-ray lines were determined using both standard and high resolution PIXE spectrometers.

Enhanced electrical properties of pulsed Sn-doped (-201) β-Ga2O3 thin films via MOCVD homoepitaxy

Pulsed Sn doping (PSD) homoepitaxial gallium oxide (Ga2O3) films were deposited on (-201) β-Ga2O3 substrates using metal-organic chemical vapor deposition (MOCVD). The study aims to optimize Sn doping conditions to enhance the electrical properties of β-Ga2O3 films. The influence of Sn pulse width (ranging from 0.1 min to 0.3 min) on the morphology, structure, and electrical properties of the film was investigated. The Full Width at Half Maximum (FWHM) of the (-201) crystal plane rocking curve for all doped films is <50 arcsec, indicating high crystal quality. At a Sn pulse width of 0.2 min, we achieve the optimal balance between doping efficiency and crystal quality, resulting in a resistivity of 0.0487 Ω·cm, an electron mobility of 63.5 cm2/V·s, and a carrier concentration of 1.82 × 1018 cm-3. Compared to continuous Sn doping, PSD results in approximately 157 % increase in carrier concentration and 99 % increase in electron mobility. The application of PSD allows sufficient diffusion time for Sn atoms to effectively incorporate into the film, signifying a crucial advancement in enhancing the film's electrical properties and reducing the cost of the metal organic doping source.

Effects of Minor Zn Dopants in Sn-10Bi Solder on Interfacial Reaction and Shear Properties of Solder on Ni/Au Surface Finish.

Sn-10Bi low-bismuth-content solder alloy provides a potential alternative to the currently used Sn-Ag-Cu series due to its lower cost, excellent ductility, and strengthening resulting from the Bi solid solution and precipitation. This study primarily investigates the interfacial evolution and shear strength characteristics of Sn-10Bi joints on a Ni/Au surface finish during the as-soldered and subsequent isothermal aging processes. To improve the joint performance, a 0.2 or 0.5 wt.% dopant of Zn was incorporated into Sn-10Bi solder. The findings demonstrated that a 0.2 or 0.5 wt.% Zn dopant altered the composition of the intermetallic compound (IMC) formed at the interface between the solder and Ni/Au surface finish from Ni3Sn4 to Ni3(Sn, Zn)4. The occurrence of this transformation is attributed to the diffusion of Zn atoms into the Ni3Sn4 lattice, resulting in the substitution of a portion of the Sn atoms by Zn atoms, thereby forming the Ni3(Sn, Zn)4 IMC during the soldering process, which was also verified by calculations based on first principles. Furthermore, a 0.2 or 0.5 wt.% Zn dopant in Sn-10Bi significantly inhibited the Ni3(Sn, Zn)4 growth after both the soldering and thermal aging processes. Zn addition can enhance the shear strength of solder joints irrespective of the as-soldered or aging condition. The fracture mode was determined by the aging durations-with the brittle mode occurring for as-soldered joints, the ductile mode occurring for aged joints after 10 days, and again the brittle mode for joints after 40 days of aging.

Alloy scattering to optimize carrier and phonon transport properties in PbBi2S4 thermoelectric

Ternary PbBi2S4 compound with crustal S-rich element and low lattice thermal conductivity is considered as a potential thermoelectric candidate. However, its inferior thermoelectric properties are rooted in the low electrical transport performance. Generally, enhancing electrical transport performance (power factor, PF) primarily entails optimizing the interdependent relationship between carrier mobility μ (linked to electrical conductivity σ) and effective mass m* (related to Seebeck coefficient S). In this work, we introduce the strategy of alloy scattering to independently enhance S without weakening μ and simultaneously reduce thermal conductivity, leading to a synergetic optimization of electron and phonon in PbBi2S4 thermoelectric. Heavy Sn alloying in PbBi2S4 presents uniform and orderly distribution on Pb sites as unclosed by the atomic-scale crystal structure observation. These massive Sn atom serves as scattering centers and turns the electron scattering mechanism to be dominated by alloy scattering, thus resulting in a ∼ 33% increment of S in Pb0.6Sn0.4Bi2S4. Meanwhile, Sn alloying aggravates phonon scattering further lowering lattice thermal conductivity and reaching an extremely low value of 0.34 W·m–1·K–1 at 773 K. Finally, a maximum zT of 0.68 at 773 K is obtained in Pb0.6Sn0.4Bi2S4, which is ∼ 45% higher than the pristine matrix. This study proves that the strategy of alloy scattering is effective in improving overall electrical transport properties as well as reducing lattice thermal conductivity, which paves a new way to develop high-performance thermoelectric materials.

Geometrical features, stability and electronic properties of (Cu3Sn)n clusters

Recently, significant advancements have been made in low-entropy Cu3Sn catalysts, showcasing their efficient catalytic CO oxidation capabilities. Hence, the atomic models of the Cu3Sn are worth established to further investigate their catalytic mechanisms. Here, the structural features and stability of (Cu3Sn)n clusters (n = 1–6) are investigated using the genetic algorithm combined with the density functional theory (DFT). The results reveal the structural evolution of these clusters from hollow cages to compact icosahedrons, where Cu atoms predominantly tend to grow together, while Sn atoms are dispersed at the edge positions. The Eb, Ef and Δ2E analyses show that the icosahedral (Cu3Sn)3 has a higher stability than that of its neighbors. The molecular dynamics simulations demonstrates its stability even at 1000 K. The molecular orbitals and density of states reveal that the (Cu3Sn)3 has an 1S21P61D102S21F1 superatomic electronic configuration. Electrostatic potential surfaces show that (Cu3Sn)n clusters have significant σ-hole regions at the Cu atomic sites, which can make the CO stretching frequency and bond length have a large red-shift. Moreover, the adsorption energy between the (Cu3Sn)3 and CO is the largest, reaching 1.17 eV. Our work provides inferences to the structural characteristics and adsorptions of the CuSn alloys at the atomic level.

Effect of Ce Addition on Microstructure, Thermal Conductivity, and Mechanical Properties of As-Cast and As-Extruded Mg-3Sn Alloys.

In the present research, the impacts of Ce additions at various concentrations (0, 1.0, 3.4, and 4.0 wt.%) on the evolution of the microstructure, mechanical properties, and thermal conductivity of as-cast and as-extruded Mg-3Sn alloys were investigated. The findings demonstrate that adding Ce caused the creation of a new ternary MgSnCe phase in the magnesium matrix. Some new Mg17Ce2 phases are generated in the microstructure when Ce levels reach 4%. The thermal conductivity of the Mg-3Sn alloy is significantly improved due to Ce addition, and the Mg-3Sn-3.4Ce alloy exhibits the highest thermal conductivity, up to 133.8 W/(m·K) at 298 K. After extrusion, both the thermal conductivity and mechanical properties are further improved. The thermal conductivity perpendicular to the extrusion direction of Mg-3Sn-3.4Ce alloy could achieve 136.28 W/(m·K), and the tensile and yield strengths reach 264.3 MPa and 227.2 MPa, with an elongation of 7.9%. Adding Ce decreases the dissolved Sn atoms and breaks the eutectic α-Mg and Mg2Sn network organization, leading to a considerable increase in the thermal conductivity of as-cast Mg-3Sn alloys. Weakening the deformed grain texture contributed to the further enhancement of the thermal conductivity after extrusion.