Barium-Strontium Titanate/Porous Glass Structures for Microwave Applications

Abstract

Based on porous silicate glasses obtained by ion exchange, glass-ceramic materials containing a solid solution of barium-strontium titanate with a dielectric constant of more than 100 at microwaves, were synthesized for the first time. Glass-ceramic structures were studied using X-ray diffraction, secondary electron microscopy, Mössbauer spectroscopy and porometry methods. Electrical characteristics such as permittivity and losses of as-prepared and annealed in oxygen medium samples were also investigated at microwaves. It was shown that the method of obtaining porous glasses, due to ion exchange between KFeSi glass and LiNO3 and NaNO3 melts, allows for controlling a wide range of pore sizes and makes it possible to form glass porous structures with pores of the required size. The efficiency of the process of filling a porous matrix with a ferroelectric filler was investigated and the average depth of its penetration was estimated. It was shown that annealing glass-ceramic structures in an oxygen environment had a positive effect on their structural and electrical characteristics. Glass-ceramic structures demonstrate a significant increase in permittivity and a decrease in losses after high-temperature treatment in oxygen.

Composite Metamaterial: Ferrite Matrix with Ferroelectric Inclusions

“…This approach enables adjustment of the size, shape and relative location of ferroelectric inclusions by selecting the type of matrix. To implement multiferroic FE meta-structures, magnetic porous glasses are used as matrices [23]. The conditions and temperature of synthesis, and the chemical purity, density, grain size, and alloying impurities, significantly affect the dielectric properties.…”

Synthesis and Characterization of a Porous Ga2O3 Material with a Low Dielectric Constant

“…Polymer and ceramic materials play a vital role in the substrate and packaging industry mainly because of their low dielectric constant and low dielectric loss. − Compared to polymers, ceramic materials especially stand out for their longer lifetime, mechanical robustness, and excellent thermal stability, especially at high temperatures . Previous literature indicates that the absence of pores is a crucial extrinsic parameter to achieve a lower dielectric constant. , Additionally, high purities and uniform particle size, along with a sintered morphology, play a significant role in producing low-loss ceramics. Considering all the requirements and combining the necessary factors, synthesis of the new candidate porous Ga 2 O 3 was carried out.…”

“…11 Previous literature indicates that the absence of pores is a crucial extrinsic parameter to achieve a lower dielectric constant. 12,13 Additionally, high purities and uniform particle size, along with a sintered morphology, play a significant role in producing lowloss ceramics. Considering all the requirements and combining the necessary factors, synthesis of the new candidate porous Ga etc.…”