Effect of Carrier Doping on Physical Properties of A-Site Ordered Perovskite CaCu3Ti4O12

Resistivity, Hall effect, Seebeck effect, magnetization and elastic constant of A-site ordered perovskite ACu 3 Ti 4 O 12 with A = Ca, Na, Y, Yb and their mixed compounds have been measured as a function of temperature. Hall effect and Seebeck effect show that the type of carrier for CaCu 3 Ti 4 O 12 , YCu 3 Ti 4 O 12 and YbCu 3 Ti 4 O 12 is electron, and NaCu 3 Ti 4 O 12 is hole. Effect of doping on the magnetic state was investigated. Magnetization shows different behavior dependent on the doped element. Elastic constant shows an elastic anomaly associated with the antiferromagnetic transition at around T N = 24 K.