Tunability and dielectric properties of Ba_0.55Sr_0.45TiO₃/MgO composites prepared by heterogeneous precipitation method and sol-gel method

ABSTRACT

45wt%Ba_0.55Sr_0.45TiO₃-55wt%MgO composites prepared by heterogeneous precipitation method and sol-gel method were synthesized. Coating layer was obviously observed in the calcined BST/MgO particles prepared by heterogeneous precipitation method and sol-gel method, but it disappeared in the composites after sintering because of the grain growth of MgO. Compared to the sample prepared by conventional solid-state reaction method, higher tunability and higher dielectric constant while lower dielectric loss was achieved in the BST/MgO composites prepared by heterogeneous precipitation method and sol-gel method. This result was attributed to the difference of Mg element content in BST grain. This study shows that using the heterogeneous precipitation and sol-gel method effectively improved the properties of the BST/MgO composites.

KEYWORDS:

• Barium strontium titanate and magnesium oxide
• tunability
• heterogeneous precipitation
• sol-gel
• substitution

Funding

This work was financially supported by the Defense Industrial Technology Development Program of China (No. A1420080168), the National Nature Science Foundation of China (No. 51302093) and the Fundamental Research Funds for the Central Universities of China (HUST, 2015MS017).