イソトープで濃縮された立方ボロンナトリドの超高熱伝導度
Ke Chen1, Bai Song2, Navaneetha K Ravichandran3
1Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
まとめ
濃縮ボロンイソトープを持つ立方体ボロンニトリド (cBN) 結晶は,1600W/m·Kを超える超高熱伝導性 (κ) を表している. この発見は,CBNの
科学分野:
- 材料科学
- 固体物理学
- クリスタル の 成長
背景:
- 高熱伝導性 (κ) の材料は,技術的進歩と基本的な科学的な理解に不可欠です.
- 同位体組成は,熱伝導を含む材料の特性に大きな影響を及ぼします.
研究 の 目的:
- 立方ボロンニトリド (cBN) の熱伝導性に対するボロン同位体濃縮の影響を調査する.
- cBNにおける κ の同位体強化を,酸化物や酸化物などの他の基化合物と比較する.
- 先進的な電子および光電子アプリケーションのためのcBNの可能性を評価する.
主な方法:
- ボロンイソトープ (10Bと11B) を制御した立方体ボロンニトリド (cBN) の結晶の成長.
- 同位体で濃縮されたcBN試料の室温での熱伝導性 (κ) の測定
- cBN,ボロン・フォスフィード,ボロン・アルセニドにおけるイソトープ効果の比較分析
主要な成果:
- 室温で同位体濃縮CBNで,超高熱伝導度 (κ) を1メートルケルビンあたり1600ワット以上達成した.
- cBNと比較して,ボロン・フォスフィードとボロン・アルセニドの κ の同位体強化が著しく低いことが観察されました.
- 同位体質の乱れは,ボルン・フォスフィードとボルン・アルセニドのフォノンに減少した効果があることが実証された.
結論:
- 同位体で設計されたcBNは,多くの確立された材料を上回る例外的な熱伝導性を示す.
- cBNの広帯域差 (6.2 eV) と超高 κは,マイクロエレクトロニクスにおける熱管理の主要な候補として位置づけられています.
- cBNは,優れた熱性能を必要とする高性能の電子および光電子アプリケーションに非常に有望です.
関連する概念動画
Hybridization of Atomic Orbitals I
64.7K
The mathematical expression known as the wave function, ψ, contains information about each orbital and the wavelike properties of electrons in an isolated atom. When atoms are bound together in a molecule, the wave functions combine to produce new mathematical descriptions that have different shapes. This process of combining the wave functions for atomic orbitals is called hybridization and is mathematically accomplished by the linear combination of atomic orbitals. The new orbitals that...
64.7K
Types of Semiconductors
1.3K
Intrinsic semiconductors are highly pure materials with no impurities. At absolute zero, these semiconductors behave as perfect insulators because all the valence electrons are bound, and the conduction band is empty, disallowing electrical conduction. The Fermi level is a concept used to describe the probability of occupancy of energy levels by electrons at thermal equilibrium. In intrinsic semiconductors, the Fermi level is positioned at the midpoint of the energy gap at absolute zero. When...
1.3K
Lattice Centering and Coordination Number
11.2K
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...
11.2K
Atomic Nuclei: Nuclear Spin State Population Distribution
2.2K
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
2.2K
Network Covalent Solids
15.9K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
15.9K
Nuclear Transmutation
20.3K
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed...
20.3K


