The investigation of the influence of oxygen concentration in the gas mixture on nanodispersed oxides synthesis

Abstract

Thermal effects in cathode space of low-pressure arc discharge, which contribute to the synthesis of nanopowders with an average particle size of less than 10 nm, are considered. One of the most important parameters, characterizing the cathode processes of vacuum arc, is a voltage drop across the discharge gap. All the gases demonstrate a decrease of a voltage drop across the discharge gap under the condition of increasing the gas pressure in the range of p = 10-3 – 1 Pa. Dissipation of energy of ions and electrons on gas molecules leads to rapidly heating the gas. Heat, coming from gas plasma, has a significant impact on evaporating material of a cathode. It can be assumed that a microdrop fraction, formed as a result of a cathode spraying in a liquid phase, will further evaporate in a superheated gas.