Group Of Periodic Table Research Articles

XElemNet: towards explainable AI for deep neural networks in materials science

Recent progress in deep learning has significantly impacted materials science, leading to accelerated material discovery and innovation. ElemNet, a deep neural network model that predicts formation energy from elemental compositions, exemplifies the application of deep learning techniques in this field. However, the “black-box” nature of deep learning models often raises concerns about their interpretability and reliability. In this study, we propose XElemNet to explore the interpretability of ElemNet by applying a series of explainable artificial intelligence (XAI) techniques, focusing on post-hoc analysis and model transparency. The experiments with artificial binary datasets reveal ElemNet’s effectiveness in predicting convex hulls of element-pair systems across periodic table groups, indicating its capability to effectively discern elemental interactions in most cases. Additionally, feature importance analysis within ElemNet highlights alignment with chemical properties of elements such as reactivity and electronegativity. XElemNet provides insights into the strengths and limitations of ElemNet and offers a potential pathway for explaining other deep learning models in materials science.

A computational investigation of electron transport in defected Cu thin films

Interconnects are a key component of integrated circuits (IC) and play a major role in the speed and power consumption of an IC. While surface roughness is essential for ensuring adhesion to other components in an IC, it also increases electron scattering at the surface, which can dramatically increase resistivity. Barrier layers have been introduced to mitigate the effect of rough Cu surfaces, but explanations of their behavior are varied. Using a combination of density functional theory (DFT) and the non-equilibrium Green’s function technique in conjunction with DFT (NEGF-DFT), our work aims to identify key tradeoffs between surface roughness profiles and electronic performance in copper wire interconnects, and how barrier layer atoms affect conductance across the Cu surface. We find that by removing atoms from the surface, the current allowed across the film is reduced to that of a thinner pristine film, but that as the voltage is increased the defected film recovers some of the conductance of the pristine system. By replacing the vacancy with a substituent atom (Ag, Al, Au, Co, Ir, Ni, Pd, Rh, Sn, Zn, Zr) we find that conductance across the film is intimately related to the periodic table group of the substituent atom relative to Cu.

Discovering superhard high‐entropy diboride ceramics via a hybrid data‐driven and knowledge‐enabled model

AbstractMaterials descriptors with multivariate, multiphase, and multiscale of a complex system have been treated as the remarkable materials genome, addressing the composition–processing–structure–property–performance (CPSPP) relationships during the development of advanced materials. With the aid of high‐performance computations, big data, and artificial intelligence technologies, it is still a challenge to derive an explainable machine learning (ML) model to reveal the underlying CPSPP relationship, especially, under the extreme conditions. This work supports a smart strategy to derive an explainable model of composition–property–performance relationships via a hybrid data‐driven and knowledge‐enabled model, and designing superhard high‐entropy diboride ceramics (HEBs) with a cost‐effective approach. Five dominate features and optimal model were screened out from 149 features and nine algorithms by ML and validated in first‐principles calculations. From Shapley additive explanations (SHAP) and electronic bottom layer, the predicted hardness increases with the improved mean electronegativity and electron work function (EWF) and decreases with growing average d valence electrons of composition. The 14 undeveloped potential superhard HEBs candidates via ML are further validated by first‐principles calculations. Moreover, this EWF‐ML model not only has better capability to distinguish the differences of solutes in same group of periodic table but is also a more effective method for material design than that of valence electron concentration.

Effect of cooking temperature on metal concentrations and speciation in fish muscle and seal liver

Fish and marine mammals constitute a significant part of the country food diet of many Indigenous communities in Canada. These animals sometimes accumulate essential elements as well as elevated levels of toxic metals. We experimentally assessed how changes in cooking temperature (23–99 °C by boiling) modified elemental concentrations in whitefish muscle and grey seal liver (two organs commonly consumed in some northern communities). Wet and dry elemental concentrations changed linearly as a function of temperature, and two patterns were observed: methylmercury, selenium, and rare earth elements tended to remain associated with the food during cooking, whereas alkali, alkaline-earth metals, and arsenic were significantly transferred to cooking juices. Mass balances indicated that speciation of mercury was stable during cooking. Because elements generally behaved similarly as those of their periodic table group or their ecotoxicological classes (A, B, intermediate), we propose that elemental behavior during cooking is partly a function of chemical affinity, and this relationship can be used to predict the behavior of data-poor elements of emerging concern, such as technology-critical elements. Furthermore, the marked increases and decreases in elemental concentrations during cooking (e.g., −14% As and +39% Se in whitefish; −22% Cd and +55% Hg in seal liver, on a wet weight basis) should be considered when assessing risk because current exposure models usually only consider elemental concentrations in raw food.

Alloying behavior of W and Mo in the as-cast dual-phase FeNiCrAl multi-component alloys

The W and Mo are in the same groups of periodic table and are usually used as solid solution elements. In this investigation, the minor alloying behaviors of W and Mo in Fe37Ni36Al17Cr10 alloy were explored. The addition does not change the casting microstructure greatly, with dendrite region of FCC + B2 and inter-dendrite region of FCC phase. For tensile properties at ambient temperature, as-cast Fe36Ni36Al17Cr10Mo1 alloy exhibited higher yield strength and fracture strength compared with Fe37Ni36Al17Cr10 alloy. Then, dual-phase alloys with Mo content of 2 and 3 at% were further designed and carefully studied. It is found that a nano-scale structure occurred in as-cast Fe35Ni36Al17Cr10Mo2 alloy, where a large number of spherical BCC precipitates are distributed in the dendrite region of B2 phase. Meanwhile a mixture of irregular B2 phase and FCC phase is contributed to the inter-dendrite area. The Fe35Ni36Al17Cr10Mo2 alloy exhibited the most excellent and comprehensive mechanical properties due to the fine structure and its high work hardening ability. The yield strength, ultimate tensile strength and fracture elongation of as-cast Fe35Ni36Al17Cr10Mo2 alloy are 863 ± 20 MPa, 1285 ± 17 MPa and 16.0 ± 1.0 %, respectively, which is higher than the most of reported dual-phase as-cast FeNiCrAl multi-component alloys.

On physical analysis of free Gibb’s energy based on topological indices for nickel sulfide

Nickel sulfides are inorganic compounds of chalcogens and transition metals with formula of NiSx, where nickel is from 10th group and sulfur is from 16th group of periodic table. Topological indices play a key role in analyzing and understanding the topology of chemical compounds. In the chemical structure of any compound, atoms are considered as vertices, while the bounds between these atoms are edges. The purpose of this paper is to analyses the structure of nickel (II) sulfide. Moreover, we have computed the topological indices of molecular structure of nickel (II) sulfide. The regression models between the standard molar free Gibb’s energy, specific heat and each topological index of nickel (II) sulfide for different formula units have been developed. The basic purpose of these regression models is to develop a relationship between free Gibb’s energy GE, specific heat Cp and topological indices of nickel (II) sulfide. More preciously, we provided a new direction in this field of research to analysis the physio-chemical properties like Gibb’s energy using the concept of chemical graph theory.

Density functional theory assessment of the lithiation thermodynamics and phase evolution in si-based amorphous binary alloys

Development of novel alloy-based anodes has the potential to increase the energy storage capacity of current Li-ion based energy storage technology. In particular, Si-based anodes are of interest due to their high theoretical capacity, but suffer from poor cycle and calendar life stemming from large volumetric expansion and a non-passivating solid-electrolyte interface. The addition of amorphous components to the Si anode has been shown to improve the mechanical and chemical stability during lithiation. In this study, we use density functional theory (DFT) to probe the thermodynamics of amorphous alloy formation in a range of binary Si-X alloy systems, where X constitutes any element from periodic table groups 1-17. The alloying elements are classified as active or inactive components based on the reactivity with Li, where active elements form stable binary compounds with Li and inactive elements do not. We find that when alloying inactive elements, most inactive components do not fully reduce and hence result in the extrusion of metallic phases. Formation of Si-X compounds with no reactivity to Li results in deactivation of Si and decreased capacity. Alloying with Li-inactive elements also bypasses early Si lithiation stages and decreases the onset potential for lithiation. Most of the Li-active elements do not form stable Si-X binaries or Li-Si-X ternaries, resulting in lithiation potentials composed of voltage steps matching those of the base elements (Li x X and Li x Si), while the others may not be of much practical use due to their high lithiation potentials or preciousness, but may buffer against volumetric expansion.

Influence of periodic heteroatom substitution in the aryl rings on optical properties and thermal stability of diarylethene derivatives

Photochromic diarylethene derivatives are one of the most promising candidates for various applications in optoelectronic devices. The heteroatom substitution of the aryl groups of diarylethene derivatives could greatly influence their optical properties and thermal stability. For example, the diarylethene derivatives with two thiophene rings (Dithienylethenes) have longer absorption wavelength, better fatigue resistance, sensitivity and thermal bistability than those with two furan rings. To further understand the influence of the heteroatom substitution in aryl rings, a series of diarylethene derivatives with different heteroatoms in IV (C, Si, Ge), V (N, P, As), and VI groups (O, S, Se) of Periodic Table were theoretically explored with DFT/TD-DFT functionals. According to the predicted results, the substituent effects of increasing atomic weights could influence the optical properties, the relative energies, the thermal bistability of the open isomer and the closed isomers. The maximum optical absorptions of the closed isomers and the open isomers could be finely tuned by these heteroatom groups in visible region of 395∼522 nm and in ultraviolet region of 300∼341 nm, respectively. The diarylethene with Se substituent diarylethene was predicted to have the best thermal bistability of all the nine substitutions and also have comparable photochomic properties than widely-used S diarylethene (Dithienylethenes). As 6π-electron system is indispensable part for nearly all known diarylethene derivates, the study probably provides a useful guideline for the future design of novel Se substituent diarylethene compounds with tunable photochromic properties and improved thermal bistability.

Synthesis of colloidal ZnS quantum dots

Nanomaterials are important class of materials due to their size and shape-dependent properties as compared to bulk materials. As a result, nanomaterials are increasingly interested in the technological applications of fundamental research. Among these semiconductor quantum dots (QDs) are a significant class of nanomaterials. Zinc Sulfide (ZnS) is an important semiconductor belongs to II–VI group in periodic table, a wide bandgap semiconductor, bulk energy gap 3.6 eV, with exciton binding energy of 39 meV, which is easily synthesizable material and chemically stable as compared to other chalcogenides and hence many research pronounced on zinc sulfide. Herein, we report the synthesized of Zinc Sulfide QDs by the chemical precipitation method using thioglycolic acid (TGA) as a capping agent and hydrazine hydrate-sulphur complex plays avital role in the growth ZnS QDs. The synthesized ZnS QDs were characterized using UV–visible absorption spectroscopy, photoluminescence spectroscopy (PL) , XRD, FTIR, SEM and TEM. To support the formation of ZnS QDs, XRD spectrum results the arrangement of ZnS in the cubic crystal system. The estimated particle size is 2.62 nm. The ZnS QDs are stable, fluorescent and spherical in shape as noted by the results of the PL spectral analysis and TEM images. The produced ZnS QDs are amorphous in nature and can be used in the applications like sensors, Field Emitting Diodes (FET), electroluminescence, flat panel displays and photocatalysis.

Importance of Interfacial Structures in the Catalytic Effect of Transition Metals on Diamond Growth.

Here, using ab initio calculations, we investigated the interaction between transition metals (M) and diamond C(111) surfaces. As a physical parameter describing the catalytic effect of a transition metal on diamond growth, we considered interfacial energy difference, ΔEint, between 1 × 1 and 2 × 1 models of M/C(111). The results showed that the transition-metal elements in the middle of the periodic table (groups 4–10) favor a 1 × 1 M/C(111) structure with diamond bulk-like interfaces, while the elements at the sides of the periodic table (groups 3, 11, and 12) favor a 2 × 1 M/C(111) structure with the 2 × 1 Pandey chain structure of C(111) underneath M. In addition, calculations of MC carbide formation for early transition metals (groups 3–6) showed that they have a tendency to form MC rather than M/C(111), which explains their low efficiency as catalysts for diamond growth. Further analysis suggests that ΔEint could serve as another parameter (catalytic descriptor) for describing catalytic diamond growth in addition to the conventional parameter of the melting temperature of M.

Mineralizer-free synthesis of orthorhombic arsenic-phosphorus alloys

Phosphorus and arsenic belong to the same group of periodic table and especially the former is very intensively studied. Despite this, under normal conditions, phosphorus has an orthorhombic structure whereas arsenic is rhombohedral. Research concerning the orthorhombic allotrope of arsenic is very scarce due to its limited availability and in addition, As-P alloys have been predicted to possess unique features. In this manuscript, we studied the formation of As-P alloys using condensation of vapor in various As-P ratio in the range of 50 to 100 at.% of arsenic. We observed the formation of orthorhombic arsenic in the range of 50 to 70 at.% of arsenic, While for 80 at.% and 90 at.% the rhombohedral structure of arsenic remained unchanged. The formation of orthorhombic true van der Waals As-P alloys was obtained without addition of any mineralizers such as copper or tin iodides providing high purity material.

Developing Instagram-Based E-Poster for Learning the Concept of Alkaline Group of Periodic Table

This research aimed at developing e-poster as learning media, analyzing how students respond to the e-posters uploaded to Instagram. This R&D research utilized an ADDIE model of development consisting of five stages: analysis, design, development, implementation, and evaluation. The research took place during even semester at the Department of Chemical Education, Faculty of Education and Teacher Training, Universitas Syiah Kuala. A total of twenty-four students (4 male and 20 female) who enrolled in the course of "elements and compounds of primary groups" voluntarily took part in the research subjects. We collect the data using the following instruments: A validity assessment form, a questionnaire for students, and an active Instagram account necessary for uploading the contents and monitoring students' activity on the platform. The results show that the validity score of e-posters was 97.5%, and 89 % of students responded positively to the media, and the vast majority of students would prefer to learn using e-posters in the future. The findings indicated that e-posters could contribute as alternative learning media to help students understand the concept of alkali group elements

Mechanical anomalies in mercury oxalate and the deformation of the mercury cube coordination environment under pressure

In a recent work, the extremely anomalous mechanical behavior of the anhydrous zinc and cadmium oxalates was discovered. In this paper, the mechanical behavior of the anhydrous mercury oxalate containing the remaining transition metal element of the IIB group of periodic table is investigated. The crystal structure and elastic properties of $${\text{HgC}}_{2} {\text{O}}_{4}$$ are determined using first-principles solid-state methods. Although the structure of mercury oxalate and the coordination environment of mercury in this compound are radically different to those of the zinc and cadmium oxalates, a great degree of similarity in their mechanical behavior is unexpectedly found. The mechanical behavior of mercury oxalate is anomalous and exhibits the negative Poisson’s ratio (NPR) and the negative linear compressibility (NLC) phenomena. Under isotropic pressure, the compressibility along the [1,0,0] crystallographic direction is negative in the pressure range from − 2.50 to 0.25 GPa. For external pressures applied in the direction of minimum compressibility, which coincides with [1,0,0], mercury oxalate exhibits negative volumetric compressibilities from 0.22 to 1.40 GPa. The increase in volume in this material is significant for pressures larger than 1.0 GPa, and the compressibility becomes − 95.6 $${\text{TPa}}^{ - 1}$$ at P = 1.36 GPa. As for the zinc and cadmium oxalates, the increase in volume is so drastic that mercury oxalate becomes unstable for pressures larger than 1.4 GPa. The NLC effect in mercury oxalate is due to the highly deformable character of the cube coordination polyhedron of mercury. The coordination structure becomes octahedral near P = 1.3 GPa, just before its structural instability.

A study on sodium - the fast breeder reactor coolant

Sodium, the second alkali metal in the first group of periodic table is highly chemically reactive. Sodium is widely used in pharmaceutical industries to manufacture lifesaving medicines. Liquid sodium is an excellent reducing agent and heat transport medium, which makes it an important industrial material. The application of this element in liquid form at high temperature as a coolant in fast breeder nuclear reactors necessitated development of sodium technology. Physical, chemical and nuclear properties of sodium led to the choice of sodium as the universally accepted fast breeder reactor (FBR) coolant. The manufacturing of sodium is by electrolysis process. The design and manufacturing requirements of high temperature liquid sodium system components are successfully addressed. Special type of sensors needed for high temperature liquid sodium system are specifically designed and developed. Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam is involved in the development of sodium technology in India. Sodium technology is matured to an extent and around twenty FBRs with sodium as the coolant were constructed, commissioned and successfully operated all over the world. Five sodium cooled fast reactors are currently in operation including fast breeder test reactor (FBTR) in India. Prototype fast breeder reactor (PFBR) is in the advanced stage of commissioning at Kalpakkam. This review paper explains the choice of sodium as FBR coolant and gives highlights on the research and development took place in sodium technology all over the world especially in India with an aim to give an exposure to this technology to the academic community.

Simulation of thermal processes on the electrode of a miniature protective spark gap

The article discusses the issues that arise when determining the temperature in the region of the cathode spot in miniature protective spark gaps. The modeling principle is used to study the temperature field on the spark gap electrode. A mathematical model of the process is compiled on the basis of the balance of power entering the cathode spot and its removal inside the cathode due to thermal conductivity. A numerical solution of the obtained nonlinear heat equation with inhomogeneous boundary conditions by the finite-difference method is presented. The authors compared the found temperatures in the cathode spot for metals of the fourth and fifth groups of the Mendeleev's Periodic Table with the corresponding melting points of the selected metals. A complete correlation was obtained between these temperatures. Simulation of thermal processes in the region of the cathode spot on the electrode made of 42NA-VI alloy has been carried out. The results are presented in the form of diagrams.

Recent Advances in Hybridization, Doping, and Functionalization of 2D Xenes

AbstractThe emerging monoelemental 2D materials named as Xenes including borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene, bisthumene, selenene, and tellurene, have attracted rising attention experimentally and theoretically. Because of their excellent and versatile physical, chemical, electrical, and optical advantages, Xenes have been shown or have been predicted to have excellent performance in nanotechnology applications, addressing challenges and advances in electronics, energy, healthcare, and environment. In this review, the basic fundamentals in the classification of the periodic table group and the synthesis methods for the emerging materials are summarized. Then, the hybridization, doping and functionalization of 2D Xenes, and their corresponding applications are presented. Furthermore, a summary of research progress on 2D Xenes and the challenges and perspectives for their further development are discussed.

Sources of parasitic features in the visible range of oxide transparent ceramics absorption spectra

AbstractThis research focused on the identification of parasitic signal sources introduced by sintering under reductive atmospheres of oxide transparent ceramics. The examination encompassed a wide set of materials, like Mg‐spinel, magnesia, alumina. YAG, yttria, zirconia and titania, so as to allow one to detect general rules if operating. The main finding is the dependence between the ability of such ceramics to generate, under reductive conditions, intrinsic parasitic light‐absorbing centers and their composition and structure. Thus it was determined that oxides based on transition element cations have ,in this sense, abilities not present in the case of oxides of elements from the main periodic table groups. The reason is the possibility of non‐absorbing transition cations to be reduced to oxidation states that absorb light. Drive toward reduced oxidation states is motivated by the stabilization energy associated with the ligand fields acting upon the such cations. It has been also found out that YAG lattice distortion, by dopants like tetravalent silicon or zirconium facilitates reduction of Y 3+ to Y 2 + (a light absorbing, d1, cation).Oxygen vacancies do not significantly influence visible light absorption. Carbon atoms penetrate inside ceramics, even dense ones and cause achromatic tints formation.

Influence of ions on diamond resorption

The paper presents a summary of extensive experiments on diamond resorption rates in presence of various ions performed at Prof. Rudenko lab at Moscow State University. For the first time all experimental data are shown together allowing direct comparison. Surface features of the samples etched in different conditions were studied using optical, scanning electron and atomic force microscopy. It is shown that catalytic theory of diamond resorption, a variant of topochemical adsorption theory of crystal etching, explains dramatic differences between activities of ions from different groups of periodic table on diamond resorption rate at least on qualitative level. Strong variations in surface features on diamonds etched in presence of ions with various catalytic activities are observed.

A Modified Townes-Dailey Model for Interpretation and Visualization of Nuclear Quadrupole Coupling Tensors in Molecules

We propose a modified Townes-Dailey (TD) model to help interpret and visualize experimentally measureable nuclear quadrupole coupling tensors (thus the electric field gradient tensors) in molecules. We show that, within the framework of the TD model, each principal component of the nuclear quadrupole coupling tensor is directly related to a new quantity termed as the valence p-orbital population anisotropy (VPPA or ΔP) in the same direction. While the proposed model is a simple reformulation of the original TD model thus does not introduce new physics, the concept of VPPA makes it possible to directly interpret as well as visualize, in a much straightforward way, the experimentally determined nuclear quadrupole coupling tensors in molecules. We illustrate the utilization of VPPA using nuclear quadrupole coupling tensors for 11B, 14N, 17O, 35Cl, 87Br, and 127I nuclei in a variety of molecules. We propose to use VPPA or ΔP ellipsoid representation as a means of visualizing/displaying nuclear quadrupole coupling tensors in the molecular frame. We show the usefulness of the VPPA concept in providing a unifying explanation for seemingly different types of molecular interactions such as hydrogen bonding, halogen bonding, and frustrated Lewis pairs. We further suggest that VPPA can be used as a universal measure of the ability of any element in the entire p-block of the periodic table (groups 13-16) to interact with nucleophiles (e.g., formation of chalcogen, pnictogen, tetrel, and triel bonds).

Description of learning difficulties on atomic structure and periodic table topics of tenth grade students in SMAN 7 Padang

This descriptive research was done on atomic structure and periodic table topics in SMAN 7 Padang. On these topics, students had difficulties on achieving learning goals where only 38% students could achieve the minimum defined criteria. This research aims to determine percentage of learning difficulties in all learning indicators and find factors that cause learning difficulties. 57 tenth grade students as research sample were obtained through cluster sampling technique. Research instruments used were diagnostic test and questionnaire and data were then analyzed descriptively. Analysis showed that learning difficulties were 91.2%, 13.2%, 88.3%, 51.5%, 70%, 64%, 84%, 84%, and 74.9% in the indicator of describing subatomic particles and their discovery; determining atomic number and mass number of elements and isotopes; describing atomic model according to Dalton, Thomson, Rutherford, Bohr, and wave mechanics; explaining electron configuration and orbital diagrams; determining quantum number and orbital shape; describing development of periodic system; modern periodic system; periods and groups in periodic table; and periodic trends of elements respectively. Students’ learning difficulties were influenced by school factors including teaching methods 35.8%, curriculum 47.5%, teacher relation with students 49.1 %, relation among students 41.7%, time and school discipline 33.3%, teaching tools 39.4% and school building condition 17.7%.