| 摘要 |
PURPOSE:To improve voltage non-linearity in a large current range and obtain a voltage non-linear resistor having improved life in a voltage applied state and improved surge resistant amount by oxidizing zinc vapor in an atmosphere containing at least Al or In or Ga to obtain the raw material for zinc oxide. CONSTITUTION:In case where a voltage non-linear resistor whose main component is zinc oxide as the raw material is manufactured by an indirect process according to which zinc vapor is oxidized, the zinc oxide as the raw material is obtained by oxidizing zinc vapor in an atmosphere containing at least aluminum or indium or gallium, and used. For example, an aqueous solution of each of aluminum nitrate, indium nitrate, gallium nitrate, etc., is sprayed in fine mist by an ultrasonic sprayer into the air to be introduced in an oxidation chamber 3a of a retort furnace 3 so as to be contained in the air, or a gas of aluminum bromide or aluminum iodide, etc., is caused to be contained in the atmosphere by an amount of 0.00001-0.01g/l for the amount of Al, In, or Ga. Further, a cooling duct 4 is provided to slowly cool ZnO therein to obtain zinc oxide as crystals whose grain diameter is about 0.5mum. |
