The Experts below are selected from a list of 10392 Experts worldwide ranked by ideXlab platform

Jiong Yang - One of the best experts on this subject based on the ideXlab platform.

  • discovery of high performance thermoelectric copper chalcogenide using modified Diffusion Couple high throughput synthesis and automated histogram analysis technique
    Energy and Environmental Science, 2020
    Co-Authors: Tingting Deng, Tong Xing, Madison K Brod, Ye Sheng, Pengfei Qiu, Igor Veremchuk, Qingfeng Song, Tianran Wei, Jiong Yang
    Abstract:

    Discovery of novel high-performance materials with earth-abundant and environmentally friendly elements is a key task for civil applications based on advanced thermoelectric technology. Advancements in this area are greatly limited by the traditional trial-and-error method, which is both time-consuming and expensive. The materials genome initiative can provide a powerful strategy to screen for potential novel materials using high-throughput calculations, materials characterization, and synthesis. In this study, we developed a modified Diffusion-Couple high-throughput synthesis method and an automated histogram analysis technique to quickly screen high-performance copper chalcogenide thermoelectric materials, which has been well demonstrated in the ternary Cu–Sn–S compounds. A new copper chalcogenide with the composition of Cu7Sn3S10 was discovered. Studies on crystal structure, band gap, and electrical and thermal transport properties were performed to show that it is a promising thermoelectric material with ultralow lattice thermal conductivity, moderate band gap, and decent electrical conductivity. Via Cl doping, the thermoelectric dimensionless figure of merit zT reaches 0.8 at 750 K, being among the highest values reported in Cu–Sn–S ternary materials. The modified Diffusion-Couple high-throughput synthesis method and automated histogram analysis technique developed in this study also shed light on the development of other advanced thermoelectric and functional materials.

Aloke Paul - One of the best experts on this subject based on the ideXlab platform.

  • pseudo binary and pseudo ternary Diffusion Couple methods for estimation of the Diffusion coefficients in multicomponent systems and high entropy alloys
    Philosophical Magazine, 2019
    Co-Authors: Neelamegan Esakkiraja, Keerti Pandey, Anuj Dash, Aloke Paul
    Abstract:

    ABSTRACTThe benefits of using the pseudo-binary and pseudo-ternary Diffusion Couple methods in multicomponent inhomogeneous systems are demonstrated by estimating different types of composition-dep...

  • Pseudo-binary and pseudo-ternary Diffusion Couple methods for estimation of the Diffusion coefficients in multicomponent systems and high entropy alloys
    2019
    Co-Authors: Neelamegan Esakkiraja, Keerti Pandey, Anuj Dash, Aloke Paul
    Abstract:

    The benefits of using the pseudo-binary and pseudo-ternary Diffusion Couple methods in multicomponent inhomogeneous systems are demonstrated by estimating different types of composition-dependent Diffusion coefficients. These are important for understanding the basic atomic mechanism of Diffusion and complex compositional evolutions. These were otherwise considered impossible during the last many decades. Without any options previously, sometimes the average values over a composition range of random choice were estimated, which are not the material constants but depend on the composition range and also the end member compositions. The steps and analyses for utilising the pseudo-binary and pseudo-ternary methods are first described in the Ni-Co-Fe-Mo system by producing the ideal Diffusion profiles fulfilling the concepts behind these methods. Following, the discussion is extended to the systems related to medium (Ni-Co-Cr) and high (Ni-Co-Fe-Mn-Al) entropy alloys. In fact, this is the first report showing a correct experimental method that should be followed for the estimation of the interDiffusion and intrinsic Diffusion coefficients in inhomogeneous high entropy alloys. In the end, the limitations of following these methods because of the generation of non-ideal Diffusion profiles are discussed based on experimental results. The steps are also suggested to avoid such complications. These methods are easy to adopt for research engineers. Most importantly, these give an opportunity to validate the data estimated following newly proposed numerical methods by different groups with experimentally estimated Diffusion coefficients, which were not possible earlier.

  • a novel concept of pseudo ternary Diffusion Couple for the estimation of Diffusion coefficients in multicomponent systems
    Scripta Materialia, 2018
    Co-Authors: Neelamegan Esakkiraja, Aloke Paul
    Abstract:

    Abstract A pseudo ternary Diffusion Couple technique in a multicomponent system by simplifying the mathematical complications of Onsager formalism is proposed for the estimation of composition dependent values of the interDiffusion coefficients. This is otherwise impossible following the conventional method in a system with more than three components. Other alternative methods estimate the average Diffusion coefficients over a composition range of random choice and lack physical significance. This method can be followed in a multicomponent system with any number of components on the condition that only three components develop Diffusion profiles keeping others as constant.

  • Diffusion Couple Technique: A Research Tool in Materials Science
    Handbook of Solid State Diffusion Volume 2, 2017
    Co-Authors: Aa Alexander Kodentsov, Aloke Paul
    Abstract:

    Abstract The Diffusion Couple technique is a unique and powerful experimental method which provides a framework to determine interDiffusion coefficients in solid solution systems and integrated Diffusion coefficients for stoichiometric compounds. From simple marker experiments with incremental Diffusion Couples, information about relative mobilities of species in solid solution and intermetallic phases can be obtained, and tracer Diffusion coefficients can be deduced if pertinent thermodynamic data are at hand. The Diffusion Couple technique is also a valuable approach in phase diagram studies and establishing composition–structure–property relationships in multicomponent systems. The efficiency of the method is very high. Yet, it is not without shortcomings. A number of error sources that may appear when the Diffusion Couple technique is used as “a research tool” are discussed in detail.

  • combining indentation and Diffusion Couple techniques for combinatorial discovery of high temperature shape memory alloys
    Acta Materialia, 2013
    Co-Authors: V V Shastry, Aloke Paul, V D Divya, M A Azeem, David Dye, U Ramamurty
    Abstract:

    Abstract We demonstrate the possibility of accelerated identification of potential compositions for high-temperature shape memory alloys (SMAs) through a combinatorial material synthesis and analysis approach, wherein we employ the combination of Diffusion Couple and indentation techniques. The former was utilized to generate smooth and compositionally graded inter-Diffusion zones (IDZs) in the Ni–Ti–Pd ternary alloy system of varying IDZ thickness, depending on the annealing time at high temperature. The IDZs thus produced were then impressed with an indenter with a spherical tip so as to inscribe a predetermined indentation strain. Subsequent annealing of the indented samples at various elevated temperatures, T a , ranging between 150 and 550 °C allows for partial to full relaxation of the strain imposed due to the shape memory effect. If T a is above the austenite finish temperature, A f , the relaxation will be complete. By measuring the depth recovery, which serves as a proxy for the shape recovery characteristic of the SMA, a three-dimensional map in the recovery–temperature–composition space is constructed. A comparison of the published A f data for different compositions with the T a data shows good agreement when the depth recovery is between 70% and 80%, indicating that the methodology proposed in this paper can be utilized for the identification of promising compositions. Advantages and further possibilities of this methodology are discussed.

Kuochih Chou - One of the best experts on this subject based on the ideXlab platform.

  • solid state reaction studies in fe3o4 tio2 system by Diffusion Couple method
    Journal of Alloys and Compounds, 2013
    Co-Authors: Zhongshan Ren, Xiangxin Xue, Kuochih Chou
    Abstract:

    Abstract The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by Diffusion Couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-Diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of Diffusion layer and temperature, the Diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated Diffusion activation energy was about 282.1 ± 18.8 kJ mol −1 .

Xinfeng Tang - One of the best experts on this subject based on the ideXlab platform.

  • novel ge sb te thermoelectric materials a demonstration for an efficient Diffusion Couple technique in expediently exploiting new thermoelectric materials
    Ceramics International, 2019
    Co-Authors: Jian Zhang, Yonggao Yan, Hongyao Xie, Ting Zhu, Cheng Zhang, Junhao Qiu, Lei Yao, Xinfeng Tang
    Abstract:

    Abstract An efficient Diffusion Couple technique is proposed for rapid screening of potential thermoelectric materials and it has been explored in a (GeTe)m (Sb2Te3)n pseudobinary system. In this study, a combinatorial sample library of GeTe-Sb2Te3 Diffusion Couple with rich compositions and structures was prepared by plasma activation sintering (PAS). The relationship among composition, structure and performance of the materials was revealed by analyzing the chemical composition, crystal structure and thermoelectric properties of the microdomains in the combinatorial sample library, so as to achieve the purpose for rapid identification of Ge-Sb-Te compounds with excellent thermoelectric properties. The scanning results of the Seebeck coefficient of the samples library show that the sample with potential high thermoelectric performance has a chemical composition near Ge33.1Sb13.7Te53.2. The bulk materials with compositions in the vicinity of Ge33.1Sb13.7Te53.2 were prepared by a conventional melting and PAS process. Among these bulk samples, the one with a nominal composition of Ge38Sb10.3Te51.7 achieves a maximum ZT value of 0.55 at 673 K, indicating that the constituent phases Ge0.77Sb0.154Te1 and Ge3.37Sb1.63Te6 observed in this sample could be potential candidates with excellent thermoelectric properties. These two ternary compounds should be investigated for further optimization. The results of this study provide a reference for the application of combinatorial metrology for screening and optimizing new thermoelectric materials.

Chiencheng Lin - One of the best experts on this subject based on the ideXlab platform.

  • zirconia related phases in the zirconia titanium Diffusion Couple after annealing at 1100 1550 c
    Journal of the American Ceramic Society, 2005
    Co-Authors: Kun Lin Lin, Chiencheng Lin
    Abstract:

    A Diffusion Couple of 3 mol% Y2O3–ZrO2 and titanium was isothermally annealed in argon at temperatures between 1100° and 1550°C. The phases and microstructure in the ceramic side were investigated using scanning electron microscopy and transmission electron microscopy, both attached to an energy-dispersive spectrometer. After annealing at 1100°C/6 h, zirconia grains did not grow conspicuously and evolved only traces of oxygen, resulting in t-ZrO2−x but not α-Zr. At temperatures above 1300°C, a significant amount of oxygen evolved from zirconia, reducing the O/Zr ratio, such that α-Zr was excluded from t-ZrO2−x during cooling, yielding a higher O/Zr ratio (≈2). When held at 1550°C/6 h, zirconia grains grew rapidly. The α-Zr was segregated on grain boundaries during cooling by the exsolution of zirconium from ZrO2−x, while twinned t′-ZrO2−x or lenticular t-ZrO2−x, which was embedded in ordered c-ZrO2−x, was found. The ordered c-ZrO2−x was identified by the{113} superlattice reflections of its electron diffraction patterns.