Study of photochromic and thermochromic properties in xerogels and silica films with rhodamine 610

• Grant number: 06/00764-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2006
• End date: December 31, 2006
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Dario Antonio Donatti
• Grantee: Leiliane Cristina Cossolino
• Host Institution: Instituto de Geociências e Ciências Exatas (IGCE). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil

Abstract

Recent results observed in our laboratory [1] showed that Rhodamine 610-doped Silica Xerogels could have their color progressively changed after thermal treatment at temperature of up to 400 oC. Such behavior is characteristic of thermo-chromic materials that could be used as sensors or transductors of optically controlled temperature. It was also observed that if a small area of the xerogel was illuminated by solar light concentrated by means of a lens, the region of the sample strongly illuminated would become transparent. This behavior evidences the photo-chromic effect caused by solar light or even a thermo-chromic effect caused by the local heating due to the incidence of infrared light. However, there is a lack of detailed information on what has actually occurred; which mechanisms or processes allowed the recording of optical information in our samples. And yet, what is the minimum possible storage dimension of the optical information. Therefore, the objective of this project is to prepare Rhodamine 610-doped thin silica films and to study the optical behavior of xerogels and thin films when illuminated with high-intensity light at different spectral regions.