Investigation of microwave dielectric relaxation process in the antiferroelectric phase of NaNbO3 ceramics

TL;DR

This study investigates microwave dielectric relaxation in NaNbO3 ceramics' antiferroelectric phase, revealing relaxations linked to polar nanoregions and an unusual anomaly related to phase transition disruptions.

Contribution

It provides new insights into dielectric relaxation mechanisms and phase transition behaviors in NaNbO3 ceramics at microwave frequencies.

Findings

Dielectric relaxations are observed within the antiferroelectric phase.

An unusual anomaly in relaxation strength indicates a possible phase transition.

Relaxations are associated with polar nanoregions exhibiting relaxor-like behavior.

Abstract

This letter reports microwave dielectric measurements performed in the antiferroelectric phase of NaNbO3 ceramics from 100 to 450 K. Remarkable dielectric relaxations were found within the antiferroelectric phase and in the vicinity of ferroelectric-antiferroelectric phase transition. Such dielectric relaxation process was associated with relaxations of polar nanoregions with strong relaxor-like characteristic. In addition, the microwave dielectric measurements also revealed an unexpected and unusual anomaly in the relaxation strength, which was related to a disruption of the antiferroelectric order induced by a possible AFE-AFE phase transition.