Exploration of the high temperature phase evolution of electrochemically modified Sc2(WO4)3via potassium discharge

Abstract

The activation of Sc₂(WO₄)₃via electrochemical discharge against potassium metal is investigated, as well as the subsequent thermal evolution of Sc₂(WO₄)₃. On subsequent heating from 100 to 623 K the discharged electrode exhibits essentially the same thermal expansion as that of the pure powder. Between 673 and 973 K a trigonal K₂WO₄-type phase (Pm1) is formed. Variable-temperature X-ray diffraction data indicates that upon heating from 923 K–1023 K, this phase has a thermal expansion coefficient of −1.90(10) × 10⁻⁴ K⁻¹.