Ln2Ti2S2O5 (Ln = Nd, Pr, Sm): a novel series of defective Ruddlesden–Popper phases

Abstract

The reaction of Nd2S2O, TiS2 and S at 1000 °C and subsequent chemical transport with I2 yields the new crystalline layered oxysulfide Nd2Ti2S2O5 that possesses a defective Sr3Ti2O7 structure whose cuboctahedral sites within the double-perovskite layers are empty; Nd2Ti2S2O5 is paramagnetic and semiconducting; the synthesis of the isostructural compounds Pr2Ti2S2O5 and Sm2Ti2S2O5 is also reported.