High Dielectric Permittivity and Maxwell–Wagner Polarization in Magnetic Ni0.5Cu0.3Zn0.2Fe2O4 Ceramics

Abstract

Nanocrystalline Ni 0.5 Cu 0.3 Zn 0.2 Fe 2 O 4 (NCZFO) powder was fabricated by a modified sol-gel method and then the compacted powder of NCZFO was sintered at 950, 1000, and 1100 • C for 6 h. The dielectric and electrical properties of sintered samples were investigated as functions of frequency and temperature. All of the NCZFO samples exhibit the high dielectric response behavior and show the Debye-like relaxation, which is attributed to the Maxwell-Wagner polarization and thermally activated mechanisms. The impedance spectroscopy analysis reveals that the NCZFO ceramics are electrically heterogeneous. The sintering temperature has significant influence on the dielectric dispersion behavior of the NCZFO samples, which should be mainly attributed to the large variation of the grain conduction activation energies.

The effect of Mn-doping on dielectric properties of titanate nanowires

“…This can be explained that the structure of nanotubes was destroyed and changed into particles with increasing temperature, leading to decreases in   . The semicircles diameter of the sample decreased as the increasing temperature, confirming the semiconductor-like behavior of materials [23] (see in Fig. 4(c); inset (2)).…”