Possible high temperature superconductivity in Ti-doped A-Sc-Fe-As-O (A= Ca, Sr) system

We report a systematic study on the effect of partial substitution of Sc${}^{3+}$ by Ti${}^{4+}$ in Sr${}_2$ScFeAsO${}_3$, Ca${}_2$ScFeAsO${}_3$ and Sr${}_3$Sc${}_2$Fe${}_2$As${}_2$O${}_5$ on their electrical properties. High level of doping results in an increased carrier concentration and leads to the appearance of superconductivity with the onset of T${}_c$ up to 45 K.