Synthesis of highly tetragonal BaTiO3 nanopowders by a two-step alkoxide–hydroxide route

BaTiO3 (BT) nanopowders were synthesized using the alkoxide–hydroxide route. Formation of BT nanopowders commenced at 60 °C and their amount increased with increasing temperature. However, a TiO2 second phase was always developed at temperatures higher than 100 °C due to the insufficient amount of H2O caused by its evaporation. Therefore, a two-step process is presented herein for the synthesis of homogeneous, highly tetragonal BT nanopowders. The cubic BT nanopowders were synthesized at 100 °C and subsequently heated to high temperatures (>200 °C) to increase their tetragonality. Homogeneous BT nanopowders with an average size of 94.8 nm and a high c/a ratio of 1.0081 were obtained for the specimens synthesized at 260 °C for 60 h after the formation of the cubic BT nanopowders at 100 °C for 20 h.

Graphical abstractA SEM image and a c/a ratio of BaTiO3 nanopowders formed at 100 °C with a Ba/Ti ratio of 2.0 and subsequently synthesized at 260 °C for 60 h.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► BaTiO3 nanopowders were formed at 100 °C with a Ba/Ti ratio of 2.0 and subsequently synthesized at 260 °C for 60 h. ► These BaTiO3 nanopowders exhibited a small size of 94.8 nm with a high c/a ratio of 1.0081. ► Therefore, these BaTiO3 nanopowders are good candidates for the future high-capacitance MLCCs.