Co, Cu -Doped Calcium Titanate

In recent years, much attention has been focused on CaCu3Ti40i2 (CCTO) due to the fact that it possesses a very high dielectric constant of 10 -10 at radio 

Cobalt-doped CCTO (CaCu3Ti4 ( Co ( Oi2, where = 0, 0.02, 0.1, 0.2, 0.5, and 1.0) has been synthesized using the sol-gel synthesis method. The raw materials were the analytical grade powders and Ca(N03)2 4H2O, Cu(N03)2 3H2O, Co(N03)2 6H20, Ci2H2804Ti, acetic acid, and citric acid. 

Titanium tetraisopropoxide stabilized by acetjdacetone was dissolved in isopropyl alcohol. In addition, cobalt nitrate dissolved in ethanol was mixed. These two solutions were stirred continuously using a magnetic stirrer at room temperature. Dilute nitric acid (1 1) was added slowly to this solution and the temperature rises to 90 °C to form a gel. After 45 min, sudden self-combustion occurred with the evolution of large amounts of gases and flufiy foam-Uke mass. This product was dried in a hot air oven for 24 h at 110°C. The dried powder was milled and thermally treated at 800 °C for 3h to acquire crystallized nano- (submicron) powder. The CCTO pellets were sintered at a low temperature of 950 °C. A high value of dielectric constant, on the order of 10 , was measured due to the low sintering temperature and uniform microstructure. These results indicate that the CCTO is a future material in the electronic industry for various applications. 

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