Gunn Instabilities in the Positive Column of Oxygen Discharge,

It is shown that the T layers in the KHz frequency range of oxygen discharge correspond in their characteristic properties to the instabilities observed by Gunn in GaAs semiconductors. As can be seen on the basis of measurements carried out with the aid of the double-probe method, the changes in the gradient indicate that the T layers are migrating low-field dipole domains. By considering the dissociative adduction in oxygen discharge in connection with the specific character of the generation of negative ions, it is possible to provide a qualitative explanation for the formation of the T layers and the negative differential resistance occasioned by it. According to this interpretation, the O- ions assume the function of the electrons with large effective masses in the GaAs semiconductor. Finally, it is shown that the T layers may occur also in CO2 discharge but not in discharges of gaseous halogens. Modified author abstract