Summary: | The temperature-dependent energy storage properties of four tungsten bronze-type ceramics are studied together with an investigation of their structure and temperature-dependent permittivity response, i.e., Ba<sub>6</sub>Ti<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub> (BTN), Ba<sub>6</sub>Zr<sub>2</sub>Nb<sub>8</sub>O<sub>30</sub> (BZN), Sr<sub>3</sub>TiNb<sub>4</sub>O<sub>15</sub> (STN) and Sr<sub>3</sub>ZrNb<sub>4</sub>O<sub>15</sub> (SZN) ceramics. With different cations at A and B sites, those four ceramics exhibit different crystal structures and show significantly different microstructure features and dielectric responses with changing temperatures. It was observed under SEM that BZN has smaller grains and a more porous structure than BTN. SZN shows the most porous structure among all samples, exhibiting a much lower permittivity response than other samples with no signs of phase transitions from room temperature to 400 °C. Though the energy storage response of those samples is generally quite low, they exhibit good temperature stability together with low dielectric loss. It was suggested that by obtaining a denser structure through chemical modification or other methods, those tungsten bronze ceramics with good temperature stability could be promising as energy storage devices when improved energy storage properties are achieved.
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