SOFT CHEMICAL PREPARATION AND ELECTROCHEMICAL OXYGEN DOPING OF LA2CAN-1CUNO2N+2

La2CaCu2O6 (n = 2) was obtained at temperatures as low as 800 degrees C by firing the coprecipitates from a mixed aqueous solution of La, Ca , and Cu acetates which were titrated with tartaric acid. The firing t emperature was much lower than that in solid state reactions which are usually conducted above 1000 degrees C. Both La2Ca2Cu3O8 (n = 3) and La2Ca3Cu4O10 (n = 4) were obtained at 700 degrees C in a similar prepa ration method. Low temperature firing was very important for these pre parations. A porous sintered body of La2CaCu2O6, with a relative densi ty of about 15% was also obtained using this preparation method. This porous sintered body could be effectively oxygen-doped by electrochemi cal oxidation showing the presence of a new superconducting phase with T-c around 30 K.