A New Mechanism of Thermochromism for Silica Sol-gel Materials

Summary.  In this contribution we provide evidence for thermochromic colour changes unique to silica based materials formed at low temperature by the sol-gel process. The mechanism requires the matrix and the dopant to interact in order to produce the observed colour changes. The materials formed have potential application as temperature sensitive light filters, visual temperature indicators, self-diagnostic labels for electronic devices and infrared recording media. Corresponding author. E-mail: carole.perry@ntu.ac.uk Received June 28, 2002; accepted July 30, 2002