Activated hopping of the hydroxide ion through electrodeposited thin films of electrochromic cobalt oxyhydroxide

✍ Scribed by P. M. S. Monk; N. Farooq

• Book ID: 104640837
• Publisher: Springer US
• Year: 1995
• Tongue: English
• Weight: 314 KB
• Volume: 6
• Category: Article
• ISSN: 0957-4522
• DOI: 10.1007/bf00144639

✦ Synopsis

Thin films of cobalt(ll) oxyhydroxide on platinum have been prepared by electrodeposition. The chemical diffusion coefficient Dof the hydroxide ion through the material has a marked temperature dependence, showing a simple activated behaviour in the range 273-292 K. The activation energy to ionic movement was rather large at 54.5 kJ reel -1 which, it is proposed, is ascribable to ion hopping. When spins have changed alignment, at the Neel transition temperature TN, the activation energy more than doubled to 125 kJ reel-l; and the diffusion coefficients obtained above this temperature also increased dramatically. It is proposed that structural changes occur in the electrodeposited oxide at about TN, hence the change in activation energy.