ChemRN: Materials Characterization (Topic)最新文献

{"title":"Estimating the Effect of Aqueous Cationic Latex from the Class of Thermal Elastic Plastics on the Properties of Bitumen Emulsions","authors":"V. Zhdaniuk, V. Novakovska","doi":"10.15587/1729-4061.2021.237323","DOIUrl":"https://doi.org/10.15587/1729-4061.2021.237323","url":null,"abstract":"To produce cationic bitumen emulsions, bitumen is used, whose penetration is not lower than 90 mm-1. Such bitumen has a small plasticity interval, which leads to a deterioration in its heat resistance at elevated temperatures and narrows the scope of application of emulsions based on it.\u0000Based on the review of emulsion modification methods, the modification has been proposed that involves mixing the finished bitumen emulsions with aqueous cationic latex.\u0000The process of interaction between a bituminous emulsion and an aqueous cationic latex has been considered. A mechanism for the disintegration of the modified bitumen emulsion on the surface of mineral materials was proposed. The emulsifiers have been selected and the composition of the aqueous phase has been chosen based on the analysis of surface tension isotherms. The influence of the modification on the properties of bitumen emulsions was investigated.\u0000It was established that the main physicochemical characteristics of the interphase surface accept similar values for the aqueous phase and emulsions based on it.\u0000It has been proven that the introduction of aqueous cationic latex quite moderately affects the basic physical-mechanical properties of emulsions, which makes it possible not to change the main technological parameters when using them.\u0000It was established that increasing the concentration of the polymer in the emulsion has a positive effect on the physical-mechanical properties of the binder. With an increase in the concentration of the polymer to 6 % the softening temperature increases by 16 °C, elasticity is 74 %, and the holding capacity at minus 25 °C is approaching 100 %.\u0000Improving the physical-mechanical properties of residual binder as a result of emulsion modification could increase the durability of layers in a roadbed based on bitumen emulsions and expand the scope of their application in the construction and repair of motorways","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129823243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Perpendicular Magnetic Anisotropy and its Voltage Control in MgO/CoFeB/MgO Junctions with Atomically Thin Ta Adhesion Layers","authors":"Tatsuya Yamamoto, T. Nozaki, K. Yakushiji, S. Tamaru, H. Kubota, A. Fukushima, S. Yuasa","doi":"10.2139/ssrn.3813385","DOIUrl":"https://doi.org/10.2139/ssrn.3813385","url":null,"abstract":"We study the perpendicular magnetic anisotropy (PMA) and the voltage-controlled magnetic anisotropy (VCMA) effect in MgO/Ta/CoFeB/MgO junctions. A few monolayers (3 − 5 A) of Ta acts as an adhesive layer, allowing for the formation of flat and ultrathin (∼ 10 A) CoFeB films with large PMA on top of MgO. In the MgO/Ta/CoFeB/MgO junctions, the diffusion of Ta to the upper CoFeB/MgO interface is effectively eliminated, and superior thermal stability up to 400◦C is demonstrated. Detailed nanostructural analyses reveal the appearance of Co-Fe compositional variation in the CoFeB layer associated with the insertion of Ta layer, which explains the observed changes in PMA and VCMA. Our results will facilitate the development of VCMA-based memory devices and also pave the way toward controlling the magnetic and electric properties of CoFeB thin films through subnanometer-scale compositional modulation.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117261370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding Crystallization, Mechanical Properties and Reactivity of Multicomponent Bioactive Glasses Through Molecular Dynamics Simulations","authors":"A. Pedone, V. Cannillo, M. Menziani","doi":"10.2139/ssrn.3807771","DOIUrl":"https://doi.org/10.2139/ssrn.3807771","url":null,"abstract":"In this study, we have applied Molecular Dynamics (MD) simulations to obtain reliable structural models of the bulk and surfaces of the 45S5 Bioglass® and three recently designed glasses in the system Na2O-K2O-CaO-MgO-SrO-P2O5-SiO2 and interpreting their different behaviour and properties. In fact, the substitution of sodium oxide with alkaline earth oxides (Ca, Mg and Sr) in the traditional 45S5 Bioglass® has been shown to be beneficial for improving the sinterability and mechanical properties of the glass maintaining optimal biocompatibility.The reduced tendency of crystallization has been associated to the increased chemical disorder around network former cations, the reduced mobility of alkaline earth cations with respect to sodium and the reduced coordination number of magnesium, which hamper the large structural re-organization necessary to the precipitation of the Na2Ca2Si3O9 crystal phase. In all the compositions, fragmented chains dominate the silica network and the network connectivity is similar. However, the increased interconnection of such chains by Mg, Ca and Sr cations makes the substituted glasses stiffer and harder than the 45S5 Bioglass®. The different reactivity of the glasses is due to the different amount of alkali cations and undercoordinated species at the glass surfaces.The approach presented provides deeper insights on the structure-properties relationships in bioactive glasses, and can be used to find precious guidelines for compositional tuning and designing innovative bioactive glass compositions with desired behaviour or property for a specific application.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133408547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural, Electronic, Mechanical and Thermodynamic Properties of Half-Metallic Rh 2FeZ (Z = Ga, In) Full Heusler Compounds from First Principles","authors":"O. E. Osafile, J. O. Umukoro","doi":"10.2139/ssrn.3646504","DOIUrl":"https://doi.org/10.2139/ssrn.3646504","url":null,"abstract":"We report on the structural, electronic, mechanical, and thermodynamic properties of Rh2FeGa and Rh2FeIn full Heusler alloys from first principles. Results for the structural analysis establishes structural stability with a negative formation energy of -0.2175 eV and -0.2082 eVfor Rh2FeGa and Rh2FeIn, respectively. The lattice constants and electronic properties compare favorably with reports from existing  literature. The compounds are both anisotropic and mechanically stable, having checked out with the Born and Huang criteria. Rh2FeIn alloy is more ductile, yet, harder, and stiffer compared to its Rh2FeGa counterpart. The Debye temperatures of 400.124 K and 267. 738 K recorded for Rh2FeGa and Rh2FeIn, respectively, is consistent with the expectation that the main group element's atomic size has an inverse relationship with the Debye temperature. Therefore, indium with the larger atomic size has a lesser Debye temperature. Both compounds obey the Dulong-Petit limit at temperatures between 400 K and 500 K. The specific heat capacity at constant volume 𝐶𝜐 of 96.5 𝐽 𝑚𝑜𝑙−1𝐾−1 and 98 𝐽 𝑚𝑜𝑙−1𝐾 −1 for Rh2FeIn and Rh2FeGa alloys suggests thermodynamic stability of the compounds at moderate  temperatures. \u0000Keywords: Density functional theory; Density functional perturbation theory; Half-Heusler compounds; Mechanical Properties;  Thermodynamic properties.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131689254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Boundary Diffusion With a Strong Kinetic Effect on Eutectic Growth","authors":"Lili Tian, Sanxuan Han, Yang Bai, Yaying Huang, X. Lei, W. Yao, Nan Wang","doi":"10.2139/ssrn.3770988","DOIUrl":"https://doi.org/10.2139/ssrn.3770988","url":null,"abstract":"The atomic attachment pathway for boundary diffusion is different from that of volume diffusion, thus leading to a stronger kinetic effect. However, it remains challenging to quantitatively determine the kinetic part from the total undercooling. In this article, the kinetic contribution is incorporated into the boundary diffusion model, and the relationships between the growth rate, interphase spacing, and undercooling are obtained, by which the kinetic effect is examined. Moreover, a polymeric eutectic system composed of polyethylene glycol 6000 and 1, 3, 5 - trioxane was chosen to check the kinetic undercooling during the phase transition. This showed that the eutectic grows via boundary diffusion and that kinetic undercooling takes up a majority of the total driving force. Our results can provide in-depth insight into the kinetic contribution during a boundary-diffusion controlled eutectic transformation.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130435179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Analysis of Conical Indentation: Proposing a Contact Area Independent Procedure Based on Strain Energy Analysis to Estimate Materials Mechanical Properties","authors":"Simón Roa, M. Sirena","doi":"10.2139/ssrn.3765775","DOIUrl":"https://doi.org/10.2139/ssrn.3765775","url":null,"abstract":"A systematic finite element analysis (FEA) of conical indentation in different isotropic elastic-plastic bulk solids was realized. In particular, the relation between the indentation Hardness (H)-to-Reduced Elastic Modulus (Er) ratio and the Elastic (Ue)-to-Total (Ut) strain energy ratio was studied. Results showed a linear dependency between both ratios as predicted by analytical studies, being the proportionality constant mainly dependent on cone semi-angle(𝜃) and material Poisson´s ratio (𝑣). A well-agreement with experimental data reported in the literature was observed for a wide variety of materials. By a simple analysis of the Oliver & Pharr method and our results, we proposed two analytical equations to calculate the H and E parameters overcoming the indenter contact area (AC) dependence in indentation data analysis. AC independent analytical procedures can become interesting to simplify the data analysis and overcome considerable uncertainties due to possible pile-up effects associated to different plastic deformation phenomena.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128759065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slow Relaxation of the Magnetization in a {Co IIIMn III} Heterometallic Brick-Wall Network","authors":"Maria-Gabriela Alexandru, D. Visinescu, S. Shova, S. Stiriba, J. Cano, F. Lloret, M. Julve","doi":"10.1016/J.POLY.2021.115118","DOIUrl":"https://doi.org/10.1016/J.POLY.2021.115118","url":null,"abstract":"","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"119916400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Structural Relaxation on Crystal Nucleation in Glasses","authors":"V. Fokin, A. S. Abyzov, N. S. Yuritsyn, J. Schmelzer, Edgar Dutra Zanotto","doi":"10.2139/ssrn.3693593","DOIUrl":"https://doi.org/10.2139/ssrn.3693593","url":null,"abstract":"Abstract Applying the Classical Nucleation Theory (CNT) to crystallization of glasses encounters some difficulties. One of the most important aspects is that this theory overlooks structural relaxation by assuming that crystal nucleation proceeds in a relaxed, metastable, supercooled liquid (SCL). Considering this assumption, the thermodynamic driving force, diffusion coefficient, and surface tension should be constant at any given temperature. Here, we performed experiments for very extended times (up to about 2,200 hours at 703K), at temperatures below the laboratory glass transition, T g = 726 K , of a lithium disilicate glass used as a model. Our results show that crystal nucleation starts concomitantly with the relaxation process of the glass towards the SCL, which strongly affects the nucleation kinetics, taking over 500 hours to reach the ultimate steady-state regime at this temperature. This very long relaxation process proceeds much slower than the well-known alpha-relaxation determining, e.g., the temporal evolution of the glass density, which takes only ~20 hours at this same temperature. Nevertheless, structural relaxation results in a decrease of the work of critical cluster formation leading to an upsurge of the nucleation rate. The increased nucleation rate mainly reflects this long structural relaxation mode of the glass and is not related to the classical transient nucleation, which has been exclusively employed so far in the interpretation of nucleation kinetics by most researchers, including ourselves, over the past 40 years. Our experimental results and analyses prove effect of glass relaxation on crystal nucleation and shed light on the alleged “breakdown” of the CNT at low temperatures.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116721812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palladium(II)-Salicylanilide Complexes, Spectroscopic, Biological, DFT Calculations and in Silico Studies","authors":"Ahmed S. M. Al‐Janabi, T. Yousef, Mohammed E. A. Al-Doori, R. A. Bedier, B. M. Ahmed","doi":"10.2139/SSRN.3745221","DOIUrl":"https://doi.org/10.2139/SSRN.3745221","url":null,"abstract":"Palladium(II)-Salicylanilide complexes of the type [Pd(k2-Saln)2] (1), [Pd(k2-Saln)2(diphos)] (2-6) (diphos = dppe, dppp, dppb, dppf, and dppmS2) and [Pd(k2-Saln)2(m-dppm)] (7) were synthesized and characterized. The salicylanidate ligand (Saln-) was bonded as bidentate chelating through the O atoms of hydroxyl and carbonyl groups in complex (1), whereas coordinated as monodentate through the O atom of hydroxyl group in complexes (2-7), and the all diphosphine ligands except dppm bonded as bidentate chelating to afford a square planner geometry around the Pd(II) ion. The dppm ligand was coordinated as bidentate bridging to afford binuclear complex. The prepared complexes displayed respectable activity against the pathogen bacteria species. Complex (5) showed the highest inhibition value against all types of bacteria, compared to the other complexes and the free ligand. On the other hand, the complex [Pd(Saln)2], showed the lowest inhibition against all types of bacteria. And the inhibition sequence of complexes is as following:(5) > (4) > (2) > (3) > HSaln > (1)Calculations of density function theory (DFT) were performed at the B3LYP/6-311G(d,p) level involved in the Gaussian 09 program to inspect the optimized structures of the chelating agent and its complexes. Docking study of the ligand was performed against the proteins of bacterial strains Streptococcus pyogenes (ID: 5GOT), Escherichia coli (ID: 1C14), Staphylococcus aureus (ID: 3BL6), and Salmonella typhimurium (ID: 3V7F) by Schrodinger suite program using XP glide protocol.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124895568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Residual Stress and Domain Switching in Freeze-Cast Porous Barium Titanate","authors":"J. Roscow, Yizhe Li, D. Hall","doi":"10.2139/ssrn.3737308","DOIUrl":"https://doi.org/10.2139/ssrn.3737308","url":null,"abstract":"In this paper, we provide the first direct evidence of enhanced domain mobility in porous barium titanate, compared to a dense sample of the same composition, facilitated by a relaxation in intergranular stress. We demonstrate that porosity can act to unclamp domains in ferroelectric ceramics, increasing the extrinsic contribution to bulk piezoelectric properties, and providing a novel route for functional property engineering in the future. Porous barium titanate with highly aligned, anisometric pores and pore volume fraction, vp = 0.52, was fabricated by the freeze casting method; dense barium titanate (relative density, Ρrel = 0.94) was fabricated for comparison. High energy synchrotron X-ray diffraction experiments with in-situ electric field dependent measurements were used to investigate the residual stress, lattice strain and domain switching contributions to electrostrain in the porous and dense barium titanate ceramics. The domain switching fraction was calculated as a function of the applied electric field. Almost twice as many domains were observed to switch in the porous barium titanate compared to the dense material at 3 kV/mm (41.7% and 21.7%, respectively), which we attribute to the significant reduction in the intergranular stress due to the high volume of zero-stiffness pores. Using a micromechanical approach, the residual stress was estimated to be 70 MPa in the dense barium titanate at 3 kV/mm compared to 40 MPa in the porous material under the same electric field, reducing to 30 MPa and 10 MPa, respectively, in the remanent state. Whilst the fraction of domain switching was enhanced, the intrinsic contribution to the piezoelectric properties was slightly reduced in the porous barium titanate compared to the dense ceramic. The findings presented in this paper demonstrate that as well as providing a route to tailor application-specific effective bulk properties, compliant and low permittivity second phases can be used to engineer the behaviour of ferroelectric composites at the lattice and domain level. This broadens significantly the microstructural design space for ferroelectric composites, which are of particular interest for piezo- and pyroelectric sensors and energy harvesters, in the future.","PeriodicalId":314762,"journal":{"name":"ChemRN: Materials Characterization (Topic)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126497559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}