Article ID Journal Published Year Pages File Type
1487130 Materials Research Bulletin 2016 5 Pages PDF
Abstract

•The glass was prepared by aerodynamic levitation method.•A temperature and frequency-independent dielectric constant (εr≈40εr≈40) under 473 K•A relaxor-like behavior was observed above 200 °C.•The low-temperature relaxation is a conduction relaxation.•The other one is a Maxwell-Wagner relaxation associated with phase boundary.

0.35La2O3 − 0.65Nb2O5 glasses were prepared by aerodynamic levitation method. The dielectric properties of the sample were investigated as a function of temperature (30 − 700 °C) in the frequency range from 100 Hz to 1 MHz. The glasses show a temperature and frequency-independent dielectric constant of ∼40 below 200 °C. A relaxor-like behavior was observed above 200 °C, which was found to be composed of two relaxations with the activation energy of 1.32 eV and 1.3 eV for the low- and high-temperature relaxations, respectively. Impedance analysis reveals that the low-temperature relaxation is a conduction relaxation associated with hopping motion of oxygen ions and the high-temperature one is a Maxwell-Wagner relaxation associated with phase boundary. The relaxor-like behavior is attributed to the combining effect of both relaxations.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
Authors
, , , , ,