Synthesis of the (Ga, Al)Sr 2Ca n−1Cu nO 2n+3, (n = 2–5) systems at ambient pressure

Abstract

Through an ambient pressure synthesis we have obtained a stable copper oxides for n > 3. Here we report a series of compounds given by ( Ga, Al) Sr 2 Ca n−1Cu nO 2 n+3 , ( n = 2–5) prepared at ambient pressure. These compounds have a structural rearrangements which is different to those synthesized with high pressure [1–3], even though the thermodynamic effects at ambient conditions do not change regardless of structural changes. By X-ray diffraction we observed that the ( Ga, Al)-based compounds, which have a tetragonal cell, are isomorphous to the ones reported by Isobe et al. [3] and Tl-based superconductor [4] respectively. For the Ga compounds the reaction temperature is 930±3°C and for the Al system is 970±3°C.