Electrical Conduction at High Fields

The study of electrical conduction mechanism under high D.C. electric fields of the order of 10$^5$ volt/meter and above in the sheet of insulating glass of thickness 1.00mm was carried out at room temperature(22.5$^{\circ}$C) The conduction process was ohmic at low D.C. electric fields but as the field strength increased the conductivity became field dependent and at high fields it exhibited some conductivity and variation in conduction current was non-ohmic. The current-voltage(I-V) characterstic showed the non-ohmic behavior in sample started at an electric fields 7.5*10$^5$ volt/meter.The log I-log V characterstic obtained two slopes in ratio 1:2(One and square) of values 1.13 and 1.74.The observed slopes in log I-log V characterstic suggested that the space charge limited conduction was operative.The current density and running temperature ranging from 40$^{\circ}$C to 100$^{\circ}$C(log \"{a}-log 1/T characterstic) at fixed voltage 1500 volt.The value of activation energy was calculated from obtained slope and which was found to be 0.231 ev, i.e. much less than 1 ev.This suggested the predominance of Electronic Conduction.