Ambient pressure synthesis of tetragonal Sr2CuO3+x

We report the synthesis of the “high pressure” tetragonal form of Sr2CuO3+xby direct reaction of stoichiometric mixtures of oxide, peroxide or carbonate of strontium and copper oxide intimately grounded in a ball mill for long periods of time. We present thermogravimetric analysis. We have determined that this phase can be obtained in the temperature range between 350 to 450°C. Above this temperature the orthorhombic structure is more stable. All the obtained samples are non-superconducting in contrast to the high-pressure obtained samples.