Exploration of the High Temperature Phase Evolution of Electrochemically Modified Sc-2(WO4)(3)via Potassium Discharge

The activation of Sc-2(WO4)(3)via electrochemical discharge against potassium metal is investigated, as well as the subsequent thermal evolution of Sc-2(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 (P3m1) 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) x 10(-4) K-1.