Structural and dielectric properties of CaCu₃Ti₄O₁₂ synthesized by sol–gel method

Abstract

CaCu₃Ti₄O₁₂ (CCTO) nanomaterials were synthesized using the low-cost facile sol-gel technique. X-ray diffraction (XRD) patterns confirmed the cubic structure of the prepared sample. Scherrer’s formula and the W-H (Williamson-Hall) plot was used to calculated the average crystallite size of the prepared sample and it was found to be 27 nm and 31.3 nm, respectively, while the strain created in the lattice is 5.008 × 10⁻⁴. Based on the absorbance plot, the band-gap (E_g) of the sample was determined using Tauc’s plot and it was found out to be 2.74 eV. The frequency dependence of dielectric permittivity (ε) and tangent loss (tan δ) of CCTO was analyzed at different temperature range from 300 K to 663 K over a frequency range from 10 Hz to 1 MHz. ε and tan δ decrease monotonically in entire frequency range and an anomalous frequency-dependent behavior was observed at different temperatures. High ε (in the range of 10⁴) was found out at lower frequency range. Electrical conductivity was also analyzed in range of frequencies and temperature, it was found out that in higher region of frequency conductivity slightly increases. The room temperature values of ε, tanδ and conductivity was 7.5 × 10³, 1.5 and 0.4 × 10⁻⁵ Ω⁻¹ m⁻¹, respectively. The reduction in E_g is achieved which was the major concern in this work. Furthermore, we have extensively studied the ε along with tan δ and ac conductivity for electronic application usage. According to these observations, CCTO is particularly prepared so that it could be suitable for microelectronic applications due to its high ε and low tan δ.

Keywords:

• Dielectric permittivity
• optical bandgap
• electrical conductivity
• sol–gel method

Acknowledgment

We express our gratitude towards the DST, New Delhi, for giving their all the support including financial to the Centre of Material Sciences, University of Allahabad, Prayagraj, under the FIST Program (Grant No. SR/FST/PSI-216/2016).

Disclosure Statement

The authors state that they have no known personal or financial conflict of interests that would affect the research presented in this study.

Data availability

Data will be provided if asked.