Studies on Copper Plates for Cuprous Oxide Rectifier (4th Report). Effect of Oxygen in Copper for Cuprous Oxide Rectifier Elements

The characteristics of rectification by cuprous oxide rectifiers consisting of copper plates containing oxygen from 0.054 to 0.0006% have been studied. (1) When tough pitch copper containing about 0.05% of oxygen was remelted and cast in vacuum or in nitrogen atmosphere, the oxygen content of copper decreased. These copper plates had good forward characteristics for rectification. (2) When cathodic copper was melted in vacuum, the rectification characteristics became good on the forward direction, but not on the reverse side. (3) After cathodic copper was melted in the air bublling oxygen or air, and cast in vacuum, these copper plates had good character in the reverse direction. (4) The results showed that S, Se and As in cathodic copper, which are very injurious to the reverse character, were decreased by oxygen, and that oxygen-free copper exhibited good characteristics on the forward and reverse directions. Oxygen in copper, left after having decreased the contents of S, Se and As in copper, was injurious in the forward direction. (5) Deoxidised copper oxygen freed copper by means of adding some elements such as P, Si or Mg which have affinity to oxygen in copper, exhibited very bad characteristics in both directions.