Abstract
β-sialons (Si6-zAlzOzN8-z) have been formed in the system Si3N4–Al2O3·AlN using hot-pressing at 1800°C under a pressure of 200 kg/cm2 in 1 atm. N2. In the spectral ranges 1050–850 cm-1 and 600–300 cm-1, certain infra-red bands decreased linearly in their frequencies as z increased. The bands in the former range are assigned to the stretching vibration of Si–N and the bands in the latter range to the bending vibration of Si–N–Si and N–Si–N groups in the β-Si3N4 three-dimensional network. When z increases, Si and N in the β-Si3N4 network are largely replaced by Al and O, respectively. This results in an increasing degree of structural disorder of the network and a decrease in the force constants for those vibrations. The decrease in the frequency can be explained by this decrease in the force constants.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call