Crystal structure and ferroelectric properties of Ca(Cu3-xMx)Ti4O12 (M = Fe and Ni) ceramics

M-substituted Ca(Cu3-xMx)Ti4O12 (CCMTO) ceramics, where M = Fe and Ni, were synthesized and the influence of M substitutions for Cu on the crystal structure and ferroelectric properties of CCMTO ceramics were investigated in this study. From the variations in the lattice parameters of CCMTO ceramics, the solubility limit of Ni substitution for Cu in CaCu3-xNixTi4O12 (CCNTO) ceramics was x = 0.2, whereas that of CaCu3-xFexTi4O12 (CCFTO) ceramics was x = 0.05. The crystal structural analysis of CCMTO ceramics revealed that the single phase of CCMTO ceramics belongs to the 123 non-centrosymmetric space group of 123; as a result, the P-r and E-c values of CCFTO ceramics at x = 0.05 were 1.8 mu C/cm(2) and 40 kV/cm, respectively. The ferroelectric behavior of CCMTO ceramics by the M substitutions for Cu may be related to the displacement of a Ti4+ cation in the TiO6 octahedra and tilting of the Ti-O-Ti angle because of the non-centrosymmetric space group. (C) 2013 Elsevier B.V. All rights reserved.