オーダーされた拡張固体における格子熱伝導性の下限を検知する: Gd117Co56Sn112 フォノンガラス電子結晶系
Devin C Schmitt1, Neel Haldolaarachchige, Yimin Xiong
1Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Journal of the American Chemical Society
|March 2, 2012
まとめ
研究者は,Gd{117}Co{56}Sn{112}という複雑な材料を合成し,格子熱伝導性が非常に低い. この発見は,理想的なフォノンガラス電子結晶に近づくことで,効率的な熱電気装置の開発を進めています.
科学分野:
- 材料科学 材料科学とは
- 固体物理 固体物理学
- 凝縮物質物理学 凝縮物質物理学
背景:
- 熱電装置の効率を向上させるには,低熱伝導率の新材料が必要です.
- ラットスの熱伝導性は,ユニット細胞の複雑性が増加するにつれて一般的に減少します.
研究 の 目的:
- ガラスのような熱伝導性を示す非常に複雑な結晶物質を合成する.
- 熱電学的応用のためのGd{117}Co{56}Sn{112}の構造と性質を調査する.
主な方法:
- 単結晶のGd{117}Co{56}Sn{112}の合成について.
- 原始的な単位細胞の体積と原子数を含む結晶構造の特徴.
- 輸送特性,熱容量,および室温での磁気化の測定.
主要な成果:
- Gd{117}Co{56) }Sn{112}は,原始ユニット細胞体積が6858 Å{3}で,原始ユニット細胞に285個の原子がある.
- 室温の格子熱伝導度 κ (((L) = 0.28 W/ (((m·K) を達成し,ガラス型でない固体で報告されている最低値の1つです.
- 室温で低電気抵抗を観測した.
結論:
- Gd{117}Co{56) }Sn{112) は,熱電学的用途に適した,非常に低い格子熱伝導性を示しています.
- この素材は"フォノン・グラス・電子・クリスタル"の理想に近付いており,熱と電気の輸送特性をバランスをとっています.
関連する概念動画
Lattice Energies of Ionic Crystals
Lattice energy represents the energy released when gaseous cations and anions combine to form an ionic solid, reflecting the strength of electrostatic interactions within the crystal. This process is fundamentally governed by Coulombic attraction between oppositely charged ions, where the potential energy varies inversely with the interionic distance and directly with the product of ionic charges. As ions approach one another, the electrostatic energy becomes increasingly negative, indicating a...
Lattice Centering and Coordination Number
The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell. The unit cell consists of lattice points that represent the locations of atoms or ions. The entire structure then consists of this unit cell repeating in three dimensions. The three different types of unit cells present in the cubic lattice are illustrated in Figure 1.
Types of Unit Cells
Imagine taking a large number of identical...
Types of Unit Cells
Imagine taking a large number of identical...
Molecular and Ionic Solids
Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...
Metallic Solids
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability. Many...
Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
Theory of Metallic Conduction
The conduction of free electrons inside a conductor is best described by quantum mechanics. However, a classical model makes predictions close to the results of quantum mechanics. It is called the theory of metallic conduction.
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...


