image and image luminescence in glass ceramic silica

This paper reports on the effect of glass ceramic silica matrix on image and image NIR and visible luminescence. Chromium-containing silica was obtained by precipitation from water-glass and chromium nitrate acid solution with thermal treatment at 1000 °C. From XRD results silica and silica–chromium samples are crystalline. The chromium emission spectrum presents two main broad bands: one in the NIR region image and other in the visible region image assigned to image and to image, respectively. This thermal treated glass ceramic silica–chromium sample stabilizes the image where image substitutes for image and also hexacoordinated image group probably as segregated phase in the system. It can be pointed out that luminescence spectroscopy is a powerful tool for detecting the two chromium optical centers in the glass ceramic silica.