材料期刊网

The temperature, frequency, and voltage dependences of the dielectric properties of 0.93Pb(Fe(1/2)Nb(1/2))O(3)-0.07PbTiO(3) single crystals were investigated in the temperature range of 100-300 K. An anisotropic colossal dielectric response was observed when the probe of the AC field was along the [100] and [111] directions. One relaxation was detected in the [100] direction, while two relaxations were detected in the [111] direction. The activation energies of the relaxations are in the range of 0.155-0.190 eV, indicating that the relaxations are probably caused by 3d electrons hopping between Fe(2+) and Fe(3+). The origin of the anisotropic colossal dielectric response can be explained by a "two-hopping path'' model. (C) 2011 The Japan Society of Applied Physics