The dielectric properties and electrical response of grain boundaries of Na1/2La1/2Cu3Ti4P12 ceramics were investigated as a function of temperature. High dielectric permittivity (6.1-8.7 x 103) and low loss tangent (0.032-0.038 at 10 kHz) were observed in Na(1/2)La(1/2)Cu(3)Ti(4)O(12)ceramics. Through analyses using complex impedance and electric modulus, it was found that the dielectric properties of Na1/2La1/2 Cu3Ti4O12 ceramics are closely related to the electrical response of grain boundaries. The investigation of non-Ohmic characteristics at various temperatures suggests that the potential barrier at the grain boundaries of Na1/2La1/2Cu3Ti4O12 ceramics is due to the Schottky effect. The giant low frequency dielectric response in Na1/2La1/2Cu3Ti4O12 ceramics is attributed to Maxwell-Wagner polarization at the grain boundaries. (C) 2011 Elsevier Ltd. All rights