Author: Jean-Claude Tedenac
Publisher:
ISBN: 9783319582696
Category : Chemistry, Inorganic
Languages : en
Pages : 46

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Author: Jean-Claude Tedenac
Publisher: Springer
ISBN: 3319582682
Category : Technology & Engineering
Languages : en
Pages : 50

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This book provides a comprehensive review of the current state of the art in silicon compounds for thermoelectric applications. Silicides are materials with good initial thermoelectric properties, which can be enhanced through tuning of their micro- and macrostructure. These compounds present various conduction mechanisms and complex band structures. Moreover, some are isotropic, and others anisotropic, which is highly beneficial for device tailoring. Silicides are a particularly attractive material for sensors, thermoelectric generators, and other applications because they are environmentally friendly, abundant, and low cost. This concise volume covers fundamentals and applications for an audience of materials scientists, chemists, solid-state physicists, and engineers.

Author: Francois D'heurle
Publisher: World Scientific
ISBN: 9814492183
Category : Science
Languages : en
Pages : 390

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Book Description
Silicides were introduced into the technology of electronic devices some thirty years ago; since then, they have been continuously used to form both ohmic and rectifying contacts to silicon. Silicides are also important for other applications (thermoelectric devices and structural applications, such as jet engines), but it is not easy to find an updated reference containing both their basic properties, either chemical or physical, and the latest applications.The 16th Course of the International School of Solid State Physics, held in Erice (Italy) in the late spring of 1999, was intended to break artificial barriers between disciplines, and to gather people concerned with the properties and applications of silicides, regardless of the formal fields to which they belong, or of the practical goals they pursue. This book is therefore concerned with theory as well as applications, metallurgy as well as physics, and materials science as well as microelectronics.

Author: Ali Allam
Publisher:
ISBN:
Category :
Languages : en
Pages : 118

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Book Description
Thermoelectric materials as electric power generators can be used in many fields, such as the conversion of automobile exhausting heat and industrial waste heat, solar photovoltaic-thermoelectric hybrid power generation, or RTG (Radioisotope thermoelectric generator) for deep space exploration. To date, most of the constituent elements of thermoelectric materials are scarce resource and are toxic, resulting in environmental pollution. Silicide materials have shown to exhibit good thermoelectric performances at high temperature without suffering from the aforementioned drawbacks. Among the silicide compounds, silicon-rich silicides MnSix, with x comprised between 1.71 and 1.75, are particularly interesting for their thermoelectric properties. These so-called higher manganese silicides (HMS) exhibit several tetragonal structures that correspond to Mn4Si7, Mn11Si19, Mn15Si26 and Mn27Si47. In this thesis, we examine from an experimental point of view the stability of these compounds. The investigations have been performed on both bulk and thin film materials. Mn4Si7 seems to be the most interesting HMS for thermoelectric applications; hence various synthesis routes have been explored for this compound. Finally, theoretical calculations, based on density-functional theory and Boltzmann's transport theory, have allowed us to predict the thermoelectric properties of substituted Mn4Si7. The objectives were to find substitutional atoms leading to an improvement of the thermoelectric efficiency of Mn4Si7.

Author: Vladimir K. Zaitsev
Publisher:
ISBN:
Category : Technology
Languages : en
Pages :

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Book Description
The silicides have obvious attractive characteristics that make them promising materials as thermoelectric energy converters. The constituting elements are abundant and have low price, many of compounds have good high temperature stability. Therefore, considerable efforts have been made, especially in the past 10 years, in order to develop efficient silicide-based thermoelectric materials. These efforts have culminated in creation of Mg2(Si-Sn) n-type thermoelectric alloys with proven maximum thermoelectric figure of merit ZT of 1.3. This success is based on combination of two approaches to maximize the thermoelectric performance: the band structure engineering and the alloying. In this chapter, we review data on crystal and electronic structure as well as on the thermoelectric properties of Mg2X compounds and their solid solutions.

Author: TRANS WORLD AIRLINES INC KANSAS CITY MO.
Publisher:
ISBN:
Category :
Languages : en
Pages : 1

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As a practical result of the contractual work on N-type thermoelement CoSi + 1% FeSi and P-type thermoelement Cr0.05 Mn0.95 i2 + 2% Ag were developed. These aterials, like most of the transition metal silicides, are stable thermally. Bonding experiments suggest that the bonding of electrical con acts to the transition me al ilicides is by no means an i superable problem. It is suggested that the silicides will be useful in the range 500 - 800 C probably in cascade with PbTe. On the theoretical side, a b sic understanding of the transition metal silicides or, indeed, any of the transition metal compounds is still lacking. The silicides remain s one of the few stable ma rials at high tempera ur s. Much could be done to optimize the transition metal silicides still further, particularly, along the lines of addition of small quantities of noble metals and the reduction of the lattice component of the thermal conductivity by substitutions of heavy metal silicides. (Aut or).

Author: Chen, Xi
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

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Thermoelectric (TE) materials, which can convert temperature gradients directly into electricity and vice versa, have received renewed interest for waste heat recovery and refrigeration applications. Higher manganese silicides (HMS) are promising p-type TE materials due to the abundance of the constituent elements, environmental friendliness, and good chemical stability. The objective of this dissertation is to establish a better understanding of the structure-TE properties relationship of HMS with a complex Nowotny chimney ladder structure. The focus of this work is on the investigations of the phonon dispersion of HMS crystals and the effects of chemical doping and nanostructuring on the TE properties of polycrystalline HMS. HMS crystals have been synthesized by the Bridgeman method for inelastic neutron scattering measurements of the phonon dispersion. In conjunction with density functional theory calculations, the results clearly show the presence of numerous low-lying optical phonon branches, especially an unusually low-energy optical phonon polarization associated with the twisting motions of the Si helical ladders in the Mn chimneys. The obtained phonon dispersion can be used to explain the low and anisotropic thermal conductivity of HMS crystals. (Al,Ge) double doping was found to be effective in modifying the electrical properties of HMS polycrystals. The peak thermoelectric power factor occurs at an optimized hole concentration of 1.8~2.2×1021 cm−3 at room temperature. On the other hand, Re substitution can suppress the lattice thermal conductivity to approach the calculated minimum value corresponding to the amorphous limit. Meanwhile, the thermoelectric power factor does not markedly change at low Re content of x ≤ 0.04 although it drops considerably with increasing Re content. Hence, the peak ZT has been improved to ~0.6 in both systems. The effects of nanostructuring on the TE properties have been studied in the cold-pressed samples and ball-milled samples. The thermal conductivity was reduced remarkably by decreasing the grain size. It is found that the grain size effects are more significant at low temperature. However, it is difficult to reduce the grain size to less than 50 nm without the formation of impurity phases by ball milling. These facts limit the ZT enhancement of the nanostructured HMS at high temperatures in this study.

Author: Shijie Wang
Publisher: Springer
ISBN: 3319510916
Category : Technology & Engineering
Languages : en
Pages : 549

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This collection offers new research findings, innovations, and industrial technological developments in extractive metallurgy, energy and environment, and materials processing. Technical topics included in the book are thermodynamics and kinetics of metallurgical reactions, electrochemical processing of materials, plasma processing of materials, composite materials, ionic liquids, thermal energy storage, energy efficient and environmental cleaner technologies and process modeling. These topics are of interest not only to traditional base ferrous and non-ferrous metal industrial processes but also to new and upcoming technologies, and they play important roles in industrial growth and economy worldwide.

Author: United States. Congress. House. Committee on Small Business. Subcommittee on Energy, Environment, Safety and Research
Publisher:
ISBN:
Category : Energy policy
Languages : en
Pages : 414

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Author:
Publisher:
ISBN:
Category : Metallurgy
Languages : en
Pages : 1622

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