Yahachi Saito – författare

Carbon forms a variety of allotropes due to the diverse hybridization of s- and p-electron orbitals, including the time-honored graphite and diamond as well as new forms such as C60 fullerene, nanotubes, graphene, and carbyne. The new family of carbon isotopes—fullerene, nanotubes, graphene, and carbyne—is called “nanostructured carbon” or “nanocarbon.” These isotopes exhibit extreme properties such as ultrahigh mechanical strength, ultrahigh charge–carrier mobility, and high thermal conductivity, attracting considerable attention for their electronic and mechanical applications as well as for exploring new physics and chemistry in the field of basic materials science. Electron sources are important in a wide range of areas, from basic physics and scientific instruments to medical and industrial applications. Carbon nanotubes (CNTs) and graphene behave as excellent electron-field emitters owing to their exceptional properties and offer several benefits compared to traditional cathodes. Field emission (FE) produces very intense electron currents from a small surface area with a narrow energy spread, providing a highly coherent electron beam—a combination that not only provides us with the brightest electron sources but also explores a new field of electron beam–related research.

This book presents the enthusiastic research and development of CNT-based FE devices and focuses on the fundamental aspects of FE from nanocarbon materials, including CNTs and graphene, and the latest research findings related to it. It discusses applications of FE to X-ray and UV generation and reviews electron sources in vacuum electronic devices and space thrusters. Finally, it reports on the new forms of carbon produced via FE from CNT.

Carbon forms a variety of allotropes due to the diverse hybridization of s- and p-electron orbitals, including the time-honored graphite and diamond as well as new forms such as C60 fullerene, nanotubes, graphene, and carbyne. The new family of carbon isotopes—fullerene, nanotubes, graphene, and carbyne—is called “nanostructured carbon” or “nanocarbon.” These isotopes exhibit extreme properties such as ultrahigh mechanical strength, ultrahigh charge–carrier mobility, and high thermal conductivity, attracting considerable attention for their electronic and mechanical applications as well as for exploring new physics and chemistry in the field of basic materials science. Electron sources are important in a wide range of areas, from basic physics and scientific instruments to medical and industrial applications. Carbon nanotubes (CNTs) and graphene behave as excellent electron-field emitters owing to their exceptional properties and offer several benefits compared to traditional cathodes. Field emission (FE) produces very intense electron currents from a small surface area with a narrow energy spread, providing a highly coherent electron beam—a combination that not only provides us with the brightest electron sources but also explores a new field of electron beam–related research.

This book presents the enthusiastic research and development of CNT-based FE devices and focuses on the fundamental aspects of FE from nanocarbon materials, including CNTs and graphene, and the latest research findings related to it. It discusses applications of FE to X-ray and UV generation and reviews electron sources in vacuum electronic devices and space thrusters. Finally, it reports on the new forms of carbon produced via FE from CNT.

Molecular carbon chains have attracted much interest for more than 130 years, but the length of chains is limited to 44 atoms even by sophisticated chemical synthesis. Recently, the artificial synthesis of long linear carbon chains, “carbynes,” has revived, and their existence was firmly substantiated using the latest advanced analytical methods, such as high-resolution electron microscopy and Raman scattering spectroscopy. Until the 1980s, graphite and diamond were the well-known allotropic forms of elemental carbon, which were two-dimensional (2D) and 3D crystals, respectively. Carbyne is the ultimate 1D nanowire with atomic diameter and its synthesis has opened prospects for versatile properties of carbon materials. Carbyne is a 1D semiconductor with a direct transition energy gap and interesting properties such as extreme mechanical strength are expected from it. This book comprehensively reviews and describes the latest chemical and physical synthesis methods, theoretically predicted properties, and possible applications of carbyne.

Molecular carbon chains have attracted much interest for more than 130 years, but the length of chains is limited to 44 atoms even by sophisticated chemical synthesis. Recently, the artificial synthesis of long linear carbon chains, “carbynes,” has revived, and their existence was firmly substantiated using the latest advanced analytical methods, such as high-resolution electron microscopy and Raman scattering spectroscopy. Until the 1980s, graphite and diamond were the well-known allotropic forms of elemental carbon, which were two-dimensional (2D) and 3D crystals, respectively. Carbyne is the ultimate 1D nanowire with atomic diameter and its synthesis has opened prospects for versatile properties of carbon materials. Carbyne is a 1D semiconductor with a direct transition energy gap and interesting properties such as extreme mechanical strength are expected from it. This book comprehensively reviews and describes the latest chemical and physical synthesis methods, theoretically predicted properties, and possible applications of carbyne.