Synthesis of Barium Cuprate by Secondary Induction Heating and its Electrical Properties

Abstract

Barium cuprate has been synthesized using secondary induction heating. It is found that the single-phase product is formed when the equimolar mixture of Ba(NO3)2 and CuO is kept in the induction furnace for 40 min at 1173 K. Reflections in the diffraction patterns are indexed in cubic syngony (space group Im3m). Parameters of the unit cell are refined applying the Rietveld method: a = = 1.82996(7) nm and V = 6.1281(7) nm3 (R Bragg = 4.42% and R f = 3.61%). Iodometric titration data show that a half of the copper atoms are in oxidized state in BaCuO2.25. Partial oxidation of copper (Cu2.5+) influences the electrical properties of the synthesized cuprate, examined using impedance spectroscopy within the range 453 K ≤T ≤ 593 K. The electrical conductivity of BaCuO2.25, which is nonstoichiometric toward oxygen, exhibits semiconducting nature with activation energy E dc = 0.29 eV.