Investigation of the transport properties and compositions of the Ca2 RE 7 Pn 5O5 series (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi)

The Ca2 RE 7 Pn 5O5 phases (RE=Pr, Sm, Gd, Dy; Pn=Sb, Bi) were successfully prepared from high temperature reactions at 1225–1300°C. These phases maintain the same structure types as the parent RE 9 Pn 5O5 phases, except for a Ca/RE mixing. The study and preparation of these phases was motivated by the desire to shift the metallic type properties of the parent RE 9 Pn 5O5 phases to a level more suitable for thermoelectric applications. …