Thin films of Li3Sc2-xFex(PO4)3 solid electrolytes, where x was 0.5 or 2, were prepared on quartz glass substrates by means of ultrasonic spray pyrolysis at substrate temperatures of 500 to 700C. Amorphous as-deposited films were converted into crystalline material by heat treatment at 800 to 1000C. Dense films which were composed of fine columnar grains were obtained by using 3 cycles of deposition and annealing. The room-temperature ionic conductivity, of a film with a composition of x = 0.5, was equal to 5 x 10-6S/cm. The superionic γ-phase of ultrasonic spray pyrolysis Li3Sc2-xFex(PO4)3, where x was between 0 and 0.6, was shown to be stabilized at room temperature. This was suggested to be caused by slight structural distortions and by changes in the interactions between Li ions during Sc3+ → Fe3+ substitution. The highest ionic conductivity at 25C was equal to 1 x 10-5S/cm; for samples with an x-value of 0.4.

Li3(Sc,Fe)2(PO4)3 Thin Films and Powders Prepared by Ultrasonic Spray Pyrolysis. A.K.Ivanov-Schitz, A.V.Nistuk, L.N.Demianets, N.G.Chaban: Solid State Ionics, 2001, 144[1-2], 133-41