Temperature minime reazioni di ossido solido di Stato per la sintesi di ossidi di nuovo con nuove funzioni

The Lanthanum copper oxide, La2CuO4, which is an end member of the prototype high-Tc superconductors (La, Sr) 2CuO4 and (La, Ba) 2CuO4, crystallizes in the ¿K2NiF4¿ structure in high temperature bulk synthesis. The crystal chemistry, however, predicts that La2CuO4 is at the borderline of the K2NiF4 stability and that it can crystallize in the Nd2CuO4 structure at low synthesis temperatures. Here we tried to get the Nd2CuO4 structure type La2CuO4 with molten hydroxides NaOH/KOH. For getting Nd2CuO4 type La2CuO4 structure we tried with different synthetic conditions with Cu rods, Cu foils, CuO sintered pellets, Cu2O pellets, CuS mineral, CuAg rod and LiOH as for reducing ,oxidizing and accelerating the kinetic reaction. We also show that phase control of K2NiF4 type La2CuO4 versus Nd2CuO4 type La2CuO4 can be achieved by varying the synthesis conditions.