High dielectric constant of NiFe2O4-LaFeO3 nanocomposite: Interfacial conduction and dielectric loss

Materials exhibiting colossal dielectric constant are the most sought-after materials due to their variety of applications in various electronics industries. NiFe2O4 and LaFeO3 belonging to the spinel and perovskite structures, respectively, were coupled into a nanocomposite by adapting a one-pot sol-gel synthesis. The ratio of NiFe2O4:LaFeO3 was varied and the synthesized materials were studied for their dielectric behaviors. Interestingly, among the samples studied, the nanocomposite with the ratio of 1:2 of NiFe2O4-LaFeO3 exhibited a high dielectric constant value of 10390 at a frequency of 1 kHz with a several-fold increase in conductivity. The high conductivity resulted in a high dielectric loss. The origin of such a high dielectric constant and loss have been attributed to the Maxwell-Wagner type space charge polarization arising from the microstructure that consists of large and continuous grain boundaries, and the conducting phase at the interface, respectively.

Automated summary

In this study, a nanocomposite of NiFe2O4 and LaFeO3 was synthesized via a sol-gel method, with the ratio of 1:2 of NiFe2O4-LaFeO3 exhibiting a high dielectric constant of 10390 at 1 kHz. The high dielectric constant and loss were attributed to the Maxwell-Wagner type space charge polarization arising from the microstructure that consists of large and continuous grain boundaries, and the conducting phase at the interface, respectively.