Thermionic Electron Emission from a Mayenite Electride–Metallic Titanium Composite Cathode

Abstract

A composite thermionic cathode consisting of 12CaO·7Al2O3 (C12A7) electride and metallic Ti (70:30 vol %) was fabricated as an electron emitter, and the thermionic electron emission properties were evaluated. A high emission current density of ∼1.4 mA cm-2 was achieved at 700 °C with an electric field of 4.0×104 V cm-1. The work function evaluated from the Richardson–Dushman equation was 2.1±0.3 eV, which coincides with the value for pure C12A7 electride and is lower than that for LaB6. Unlike the pure material, the composite has ohmic contact with metallic materials, and can be heated directly by electrical current.

Optical Conductivity of Mayenite: From Insulator to Metal

“…Mayenite, Ca 12 Al 14 O 33 , a well-known constituent of high alumina cements, was introduced in 1988 by Lacerda et al as a high oxide conductor. , Fourteen years later it was presented as a novel UV-activated electronic conductor . Since then, its applications as transparent conductor, catalyst, ionic conductor, radiation resistant material, electron emitter, and superconductor have been investigated. − Ca 12 Al 14 O 33 , a wide-band-gap oxide, is a body-centered cubic crystal that belongs to the space group I 3 d with a lattice parameter of 11.989 Å . It is a cage-like structure with two formula units and 12 cages per unit cell.…”

Cold atmospheric pressure plasma jet prepares TiO2 coating on carbon fibre for field emission and explosive electron emission

“…The Fowler-Nordheim (F-N) equation can analyse the field emission characteristics, namely, the relationship between the current density and the applied electric field. The F-N equation [42,43] is:…”

Исследование Эффекта Электронного Охлаждения. Обзор Современного Состояния Работ

“…Одной из главных на сегодняшний день проблем, стоящих на пути практической реализации данного метода, является отсутствие материалов с необходимыми физическими свойствами, однако в связи с широкой применимостью термоэмиссионных преобразователей поиск новых материалов является активно развиваемым направлением. Также активно ведется поиск новых способов уменьшения работы выхода, о чем говорит высокая публикационная активность [40][41][42][43]. Все вышесказанное свидетельствует о приоритете РФ перед иностранными корпорациями и научными учреждениями в области исследований, направленных на обеспечение электронного охлаждения элементов ВЛА.…”