Layered oxyselenides Sr2Co1−xMnxO2Cu2−δSe2: The evolution of magnetic properties tuned by the competed interactions

Anion redox as a means to derive layered manganese oxychalcogenides with exotic intergrowth structures

“…Figure 7a shows the powder pattern which was modelled in a similar way to that of the collapsed oxysulfide (Fig. 2 ) with collapse of the interlayer spacing between Sr 2 MnO 2 Se 2 slabs from 8.97 Å 47 in Sr 2 MnO 2 Cu 1.5 Se 2 to 8.34 Å and the presence of stacking disorder which was modelled as described above for the oxysulfide (Fig. 7b ).…”

“…This was heated to 900 °C at 10 °C min −1 and after a further 48 hours the furnace was turned off and the sample cooled at the natural rate of the furnace 15 , 30 . The selenide analogue Sr 2 MnO 2 Cu 1.5 Se 2 was prepared in a similar way 47 but with the starting materials: SrO (from thermal decomposition of SrCO 3 ) (2 equivalents), Mn (Aldrich >99%) (1 equivalent), Cu powder (Alfa 99.995%) (2 equivalents) and Se (Alfa 99.999%) (2 equivalents). For the selenide the pellet was heated at 5 °C min −1 to 850 °C and this was maintained for 24 h followed by natural cooling of the furnace.…”