<title>Electrochromic praseodymium oxide films</title>

Abstract

Thin films of Pr oxide were made by dc magnetron sputtering at different oxygen contents in the plasma. Films, ranging in color from dark orange (presumably PrO₂-like) to transparent, were made by varying the O₂/Ar ratio from 0.025 to 0.005. The electrochromic properties were studied under Li ion and proton intercalation. The charge capacity ranged from being comparable to that of W oxide for oxygen rich films to virtually zero for oxygen depleted films. The initially dark films showed strong anodic electrochromism and gave a rather neutral optical appearance in a device incorporating a W oxide film.