Structural, Dielectric & Ferroelectric study in lead-free Ba(Ti0.9Sn0.1)O3 ceramics for EMI shielding applications

Abstract

Perovskite materials are currently widely used in 5 G applications. We have examined a series of lead-free (Ba_1-xCa_x)(Ti_0.9Sn_0.1)O₃ (BCTS) ceramic samples (x$=0,0.01,0.05,0.1)$ which were synthesized using the conventional method. A systematic study of the structural, dielectric, shielding, and ferroelectric properties of Ca-doped BCTS ceramics was carried out. Rietveld refinement confirmed that BCTS samples had multiple phases with no other impurity phases. The crystallite size, average grain size, surface roughness, and structural mode of vibrations were determined by XRD, FESEM, and RAMAN analysis. The dielectric and conductivity properties were studied as a function of temperature (25 - 300$℃)$and frequency range of (1 kHz - 2 MHz). The maximum dielectric constant value of ~ 13,800 was observed for the composition x = 0.01 at 1 kHz. Conductivity analysis was done by using Jonscher’s universal power law (JPL) and Arrhenius equations. The ferroelectric properties of BCTS ceramic samples were investigated and the value of polarization wa_s maximum for x = 0.01 (P_s = 11.24 µC/cm²). Additionally, the shielding properties (S₁₁ and S₁₂ parameters) of BCTS ceramic pellets were examined in the frequency range of 12.4-18 GHz using a Vector Network Analyzer (VNA). The maximum total effective shielding value of 52 dB for BCTS ceramic pellets for x = 0.05 indicated good shielding behavior for high-frequency EMI shielding applications.