The structure of "orthorhombic" KAlSiO 4 ? O1 : evidence for Al-Si order from MAS NMR data combined with Rietveld refinement and electron microscopy

Dry synthesis of KAlSiO4 at temperatures from 900 to 1500°C yielded products with slightly different powder X-ray-diffraction patterns. "Orthorhombic" KxAlxSi2-x O4-O1 with x ≈ 1 was obtained as a substantially single phase after heating at 1000°C fo