Complex Dielectric, Impedance, and Electric Modulus of CuMn2O4.

Mohanta, S.; Naik, I.; Kaushik, S. D.; Mukherjee, S.; Patra, P.

Tetragonal distorted CuMn2O4 spinel has been prepared by a single-step method and its complex dielectric, impedance, and electric modulus measured with respect to frequency at different selected temperatures. In all the measurements, a frequency-dependent inflection point was observed above 170 K, revealing the cross-over in the grain and grain boundary effects in the electrical properties. Therefore, the activation energy was calculated to be E a ≈ 0.27 eV from the dielectric loss but as E a ≈ 0.2 eV from the impedance and electric modulus based on the Arrhenius nature of the relaxation time. Further, alternating-current (AC) conductivity measurements in the frequency range from 100 Hz to 1 MHz suggested hoping conduction due to small polarons.

DIELECTRICS; ELECTRIC impedance; IMPEDANCE spectroscopy; DIELECTRIC loss; ACTIVATION energy; DIELECTRIC relaxation; CRYSTAL grain boundaries

Journal of Electronic Materials, 2020, Vol 49, Issue 1, p842

0361-5235

Academic Journal

10.1007/s11664-019-07698-2