A novel sol-gel route to synthesize (Sr0.5Ba0.5)Nb2O6 ceramics with enhanced electrocaloric effect

作者：Chen Ting; Wu Shu Ya; Liu Xiao Qiang; Chen Xiang Ming

来源：Journal of Advanced Dielectrics, 2017, 7(2): UNSP 1750012.

DOI：10.1142/S2010135X17500126

<jats:p> (Sr[Formula: see text]Ba[Formula: see text])Nb<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> ultra-fine powders were synthesized by a novel sol–gel route, and the mechanism of the reaction was discussed. SrCO<jats:sub>3</jats:sub>, BaCO<jats:sub>3</jats:sub>, oxalate niobium and citric acid were used to initiate the sol–gel process, and ethylene glycol (EG) was added to further polymerize the cross-linking structure. The evolution of the (Sr[Formula: see text]Ba[Formula: see text])Nb<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> phase, the reaction process and the microstructures were investigated by X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy, DSC-TG and scanning electron microscopy. The synthesis temperature of the (Sr[Formula: see text]Ba[Formula: see text])Nb<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> powders reached as low as 1200[Formula: see text]C, and the size and morphology of the powders were controlled by temperature. By adjusting the calcination temperature, we obtained (Sr[Formula: see text]Ba[Formula: see text])Nb<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> powders with uniform sizes of 20[Formula: see text]nm to 500[Formula: see text]nm. Then, dense (Sr[Formula: see text]Ba[Formula: see text])Nb<jats:sub>2</jats:sub>O<jats:sub>6</jats:sub> ceramics were successfully prepared using these ultrafine powders. Finally, an enhanced electrocaloric effect (ECE) value of 0.35[Formula: see text]C was obtained at 100[Formula: see text]kV/cm. </jats:p>

• 出版日期2017-4
• 单位浙江大学