Internal Stress in Electrodeposited PbO₂

Abstract

The change of internal stress in the electrodeposited PbC₂ from a lead nitrate bath was observed by measuring the deflection of a thin platinum anode during electrodeposition of PbC₂ on one side of it. The crystal structure of the deposits was determined by X-ray diffraction. After the electrodeposition, the change of deflection of the deposited Pb₂ was observed under the following conditions : a) Keep the deposited PbO₂ in air or in a lead nitrate bath at constant temperatures. b) Discharge the cell, Pt/PbNO₃ electrolyte/PbO₂ deposit, by connecting it to an external circuit with some resistance. The results obtained are summarized as follows : 1) The crystal structure of α-PbO₂ was observed in the deposits which had deflected in the direction of contraction during electrodeposition, and β-PbO₂ was observed in the deposits which had deflected in the direction of expansion during electrodeposition. 2) After the electrodeposition, the deposits deflected gradually in the direction of expansion when they were kept in air or left in the bath. The amount of deflection of the deposits of α-PbO₂ was larger than that of the deposits of β-PbO₂ within the same time duration. 3) The electrodeposited PbO₂ deflected in the direction of expansion by discharging the cell, and the amount of deflection of the deposits of α-PbO₂ was larger than that of the deposits of β-PbO₂.