Enhanced Dielectric Properties of Ba_0.5Sr_0.5TiO₃/MgO Composites Prepared by Coprecipitation Derived Core–Shell Powders

Abstract

Ba 0.5 Sr 0.5 TiO 3 /MgO (BST/MgO) composite ceramics have been prepared in situ by using an oxalate precipitation process. SEM and TEM images show that oleic acid modified BST/ MgO nanocomposite exhibits helminth-like particles consisting of BST core and MgO shell. Results reveal that oleic acid modification is chemisorbed on MgO particles as a carboxylate to form MgO shell, which connects to interparticles. Accordingly, the BST particles are well surrounded naturally by a thin MgO layer in the composite ceramics. As a result, the oleic acid modified BST/MgO composite ceramics shows better dielectric properties, with permittivity of 203, loss tangent of 0.0025 (at 2.4 GHz), and tunability of 10.2%.

Regulation of the Ba/Sr Ratio of (Ba,Sr)TiO3 and Nanorod Build‐Up through a Topochemical Synthesis Method Using BaTi2O5 as the Template

“…Such substitution not only influences the ferroelectric transition, but also significantly broadens the phase transition. These properties are utilized for many electronic applications, such as multilayer ceramic capacitors (MLCC), microwave phase shifters, and uncooled infrared focal plane arrays (UFPAs) …”