High-Temperature Structural Phase Transition of K2SO4 and K2SeO4 Crystals Studied by X-Ray Diffraction

✍ Scribed by T.M. Chen; R.H. Chen

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 476 KB
• Volume: 111
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1994.1236

✦ Synopsis

High-temperature structural phase transitions in (\mathrm{K}{2} \mathrm{SO}{4}) and (\mathrm{K}{2} \mathrm{SeO}{4}) crystals have been studied by (\mathrm{X})-ray diffraction. Laue and precession photographs were taken with Mo radiation at several high temperatures. Results indicate that the symmetry of both crystals changes from the orthorhombic to the hexagonal system through structural phase transition. Possible space groups are (\mathbf{P 6}{3} /) (m m c, P 6{3} m c), or (P \overline{\mathbf{6} 2 c}) from extinction conditions in the hightemperature phases. The crystal structure of (\mathrm{K}{2} \mathrm{SeO}{4}) is preliminarily assumed to be isostructural with (\mathrm{K}{2} \mathrm{SO}{4}) in the high-temperature phase. Further studies of the crystal structure and the phase transitions of (\mathrm{K}{2} \mathrm{ScO}{4}) are required. o 1994 Acadenik Press, lnc.