2016 年 55 巻 1 号 p. 22-26
It is known that anodically-oxidized niobium (Nb) films make various colors. The driving force of coloration is considered to be thin film interference due to the Nb2O5 layer on the Nb film. In the case of the coloration due to thin film interference, there is a possibility that we can give a rewritable nature to Nb films by controlling the thickness of Nb2O5 layer. From the industrial point of view, it is preferable to give a rewritable nature to the color changeable Nb film since it may enable the Nb film to be used as new type of rewritable media such as color electronic paper. Therefore, the focus of this present work is to explore the possibility of these color Nb films as rewritable media. Our experimental data using a goniophotometer and a spectrophotometer suggest that our Nb films can be used as rewritable media by controlling preparation conditions.