Microstructure and dielectric tunable properties of Ba0.6Sr0.4TiO3-Mg2SiO4-MgO composite

Ba_0.6Sr_0.4TiO₃-Mg₂SiO₄-MgO composite ceramics were prepared by a solid-state reaction method and their dielectric tunable characteristics were investigated for the potential application as microwave tunable materials. The addition of Mg₂SiO₄-MgO into Ba_0.6Sr_0.4TiO₃ forms ferroelectric (Ba_0.6Sr_0.4TiO₃)-dielectric (Mg₂SiO₄-MgO) composites and shifts the Curie temperature to a lower temperature. The dielectric constant and loss tangent of Ba_0.6Sr_0.4TiO₃-Mg₂Si_O4-MgO composites have been decreased and the overall tunability is maintained at a sufficiently high level. The microwave dielectric properties of Ba_0.6Sr_0.4TiO₃-Mg₂Si_O4-MgO composites were evaluated. Ba_0.6Sr_0.4TiO₃-Mg₂SiO₄-MgO composites have tunability of 9.2 to 10.5% at 100 kHz under 2 kV/mm, indicating that it is a promising candidate material for tunable microwave applications requiring a low dielectric constant.