Influence of low-doped MgO on structure and properties of barium strontium titanate ceramics

Barium strontium titanate (Ba0.6Sr0.4TiO3, BST) ceramics with low-doped MgO were prepared using the traditional ceramic process. The phase structure, microstructure and dielectric properties of BST ceramics with MgO contents varied from 0.06%-0.18% were studied by means of XRD, SEM and property measurement. No second phase was observed in the low-doped MgO of BST ceramics using XRD. The grain size was decreased gradually with the increase of MgO content. The dielectric constant and loss are suppressed gradually as the MgO content increases and the Curie temperature shift to -49°C with 0.18wt% MgO content. The tunability is about 16% for BST ceramics with 0.18 wt% MgO content. The Curie point (Tc) moves to higher temperature with increasing of applied electric field. The microwave properties are optimized with MgO-doped of BST.