Here we report the synthesis of a bulk oxide diluted magnetic semiconductor (DMS) system La 1−x Sr x Cu 0.925 Mn 0.075 SO (x = 0, 0.025, 0.05, 0.075 and 0.1). As a wide band gap p-type oxide semiconductor, LaCuSO satisfies all the conditions forecasted theoretically to be a room temperature DMS. The Curie temperature (T C ) is around 200 K as x ≥ 0.05, which is among the highest T C record of known bulk DMS materials up to now. The system provides a rare example of oxide DMS system with p-type conduction, which is important for formation of high temperature spintronic devices.

Two distinct superconducting (SC) domes were discovered in the phase diagram of P-doped iron pnictide superconductors LaFeAs1−xPxO with x ranging from 0 to 1. The first SC dome is centered around x = 0.3 and then disappears as P content increases to x = 0.5. For x > 0.5, a second SC dome appears, and Tc reaches another maximum at x = 0.7. Although the maximum of Tc in the two domes is close to each other, the estimated upper critical field (Hc2) is much larger in the first SC dome, implying a difference in the nature between the two SC domes. Further band calculations and thermopower measurements suggest that there could be a Lifshitz transition in the electronic structure between the two SC domes.