Thermal expansion coefficients of doped and undoped silica prepared by means of PCVD
- Cite this article as:
- Bachmann, P.K., Wiechert, D.U. & Meeuwsen, T.P.M. J Mater Sci (1988) 23: 2584. doi:10.1007/BF01111918
The thermal expansion coefficient of silica prepared by means of low-pressure plasma-induced chemical vapour deposition has been investigated in the temperature range 20 to 750° C. Undoped, fluorine-doped (up to 5wt%), germanium-doped (up to 14 wt%), as well as F/GeO2-codoped samples were measured and compared to NBS standard silica samples. Fluorine-doped silica shows a lower thermal expansion coefficient than the NBS standard. A surprising hysteresis effect in the measured expansion curves was found. Its concentration dependence and annealing is discussed.