Structure of Deposits Obtained from Urea-Based Melt Bath Containing Co and La

Abstract

Electrodeposition was performed in an unagitated solution from a urea-based melt bath containing Co and La under galvanostatic (10–40 mA·cm⁻²) and coulostatic (10 C·cm⁻²) conditions at 403 K, and the structure of the deposits was investigated. Co deposited in a metallic state at 10 mA·cm⁻², whereas it was incorporated into deposits mainly as an oxide at high current densities of 30 and 40 mA·cm⁻². La codeposited with Co as an oxide irrespective of current density. The content of La₂O₃ increased with current density. The deposits showed a granular crystal structure and became nonuniform crystals comprising large localized granules at high current densities.