Reactive DC magnetron sputtering was used to make oxide films based on Ni, NiV0.08, NiAl0.56, NiMg0.8, and NiV0.08Mg0.5. All of these films were capable of showing electrochromism in KOH. The addition of Al or Mg increased the luminous transmittance significantly, while the charge capacity was maintained. Al- and Mg-containing films are superior to the conventional Ni oxide electrodes for applications requiring high bleached-state transmittance, such as architectural "smart windows". (C) 2003 Elsevier B.V. All rights reserved.