Spectroscopies and Electron Microscopies Unravel the Origin of the First Colour Photographs
|
| |
Authors: | Victor de Seauve Marie‐Anglique Languille Mathieu Kociak Stphanie Belin James Ablett Christine Andraud Odile Stphan Jean‐Pascal Rueff Emiliano Fonda Bertrand Lavdrine |
| |
Institution: | Victor de Seauve,Marie‐Angélique Languille,Mathieu Kociak,Stéphanie Belin,James Ablett,Christine Andraud,Odile Stéphan,Jean‐Pascal Rueff,Emiliano Fonda,Bertrand Lavédrine |
| |
Abstract: | The first colour photographs were created by a process introduced by Edmond Becquerel in 1848. The nature of these photochromatic images colours motivated a debate between scientists during the XIXth century, which is still not settled. We present the results of chemical analysis (EDX, HAXPES and EXAFS) and morphology studies (SEM, STEM) aiming at explaining the optical properties of the photochromatic images (UV‐visible spectroscopy and low loss EELS). We rule out the two hypotheses (pigment and interferences) that have prevailed since 1848, respectively based on variations in the oxidation degree of the compound forming the sensitized layer and periodically spaced photolytic silver planes. A study of the silver nanoparticles dispersions contained in the coloured layers showed specific localizations and sizes distributions of the nanoparticles for each colour. These results allow us to formulate a plasmonic hypothesis on the origin of the photochromatic images colours. |
| |
Keywords: | Ag@AgCl Becquerel Edmond EELS-LL electron microscopy photochromism |
|
|