Unveiling of physical, structural, morphological, and electrical properties of Fe2O3doped (30-x)BaO•30TiO2•40SiO2•x[Fe2O3], (0≤x≤6) glass-ceramics potential for energy storage devices

Abstract

Glass-ceramics with tuneable dielectric properties are increasingly sought after for next-generation multilayer ceramic capacitors (MLCCs) used in advanced electronic applications. However, developing compositions that simultaneously offer high dielectric constants, low dielectric losses, and excellent thermal stability remains a significant challenge. Herein, Fe<inf>2</inf>O<inf>3</inf>-doped (30-x)BaO•30TiO<inf>2</inf>•40SiO<inf>2</inf>•x[Fe<inf>2</inf>O<inf>3</inf>] (0≤x ≤ 6 mol%) glass and glass-ceramics are synthesized using a melt-quenching followed by controlled heat treatment technique. XRD is performed which indicates a transition from amorphous to crystalline structures after heat treatment, with a major phase of tetragonal fresnoite (Ba<inf>2</inf>TiSi<inf>2</inf>O<inf>8</inf>). To check the bonding mechanisms, Fourier transform infrared (FTIR) and Raman spectroscopies are performed. X-ray photoelectron spectroscopy was performed for analysing the elemental composition, and electronic state of a material. However, to study the microstructural behaviour, crystalline nature, and compositional variations, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), followed by energy dispersive spectroscopy (EDS) were also performed. Dielectric properties of the GCs are studied over 10 Hz to 1 MHz. Notably, 24BaO•30TiO<inf>2</inf>•40SiO<inf>2</inf>•6Fe<inf>2</inf>O<inf>3</inf>(BTSFC6) (x = 6 mol%) sample demonstrates improved dielectric constant (ε<inf>r</inf> = 31740.4) and low dielectric loss (Tanδ = 0.13) at 10 Hz (at 500 °C). The incorporation of Fe<inf>2</inf>O<inf>3</inf>not only enhances the AC conductivity but also modifies the electrical relaxation behaviour, as evident from modulus and Cole–Cole plots, which indicate non-Debye-type relaxation and a negative temperature coefficient of resistivity (NTCR) behaviour. Furthermore, hysteresis loop measurements were conducted, revealing that an increase in Fe<inf>2</inf>O<inf>3</inf>content in BTSFC glass-ceramics leads to a systematic enhancement in ferroelectric properties and energy storage capacity. This improvement enables material to be tailored for a wide range of applications, from low-loss dielectrics to high-energy storage devices. Therefore, this study demonstrates that strategic Fe<inf>2</inf>O<inf>3</inf>doping effectively tailors the structural and dielectric characteristics of barium-titanate silicate glass-ceramics, positioning the BTSFC6 composition as a promising candidate for the fabrication of energy storage devices in demanding thermal and electronic environments. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.