New YBaCuO superconductors are synthesized by using the standard solid state reaction method as Y5-6-11, Y7-9-16, Y5-8-13, Y7-11-18, Y156, Y3-8-11, and Y13-20-23. In 1987 the transition temperature of YBa2Cu3O7 (Y123) was increased to around 92 K by Chu and co-worker.
Recently Aliabadi, Farshchi and Akhavan found the new Y-based high temperature superconductor Y3Ba5Cu8O18 (Y358) became superconductive at 102 K. And they also proposed that in order to have a stronger superconductor with higher Tc in the YbaCuO family one should pump more holes from the chains to the oxygen sites of the planes, tending to diagonal charge order. Y123 has two CuO2 planes and one CuO chain. Y124 has one CuO double chain. Y247 has one CuO2 planes and one CuO chain, and one double chain. Y358 has a crystal structure similar to Y123 with five CuO2 planes and three CuO chains. The increasing number of CuO2 planes and CuO chain have important effect on the Tc of Y358.
The work was performed at the Department of Physics, Faculty of Science, Srinakharinwirot University and Thailand Center of Excellence in Physics(ThEP).