A study of dielectric behavior of manganese doped barium titanate–polyimide composites

Abstract

In this work, a series of BaTi 1−x Mn x O 3 -polyimide films were prepared by simple solution casting method. For the preparation of composite films firstly, manganese doped barium titanate, BaTi 1−x Mn x O 3 (where x = 0.00, 0.01, 0.03, 0.05) was synthesized by sol-gel process. The effect of Mn doping on its structural and dielectric properties was nicely explained. The highest dielectric constant value of 7,104 was obtained for BaTi 0.99 Mn 0.01 O 3 (BTMn) nanoparticles with low dielectric loss value 2.44. It was observed that Mn-doping concentration on barium titanate influences its crystal structure. Improved dielectric properties were reported for nanocomposite thin films containing BaTi 0.99 Mn 0.01 O 3 and polyimide (PI). A series of five homogeneous nanocomposite films were successfully prepared and were characterized thoroughly. The dielectric properties were studied as a function of frequency and loading percentage of BTMn in PI. The dielectric constant of the BTMn/PI nanocomposite films increased from 3.23 to 8.63 with the increase in loading percentage of ceramic from 0 to 5 wt%, respectively. The nanocomposite films were flexible with good mechanical properties and the flexibility decreased with increase in loading percentage of BTMn. The films showed high thermal stability in nitrogen atmosphere up to 571°C with 10% weight loss and also exhibited high glass transition temperature up to 337°C. K E Y W O R D S dielectric properties, inorganic materials, mechanical properties, polyimides, thermal properties How to cite this article: Kumari A, Dasgupta Ghosh B. A study of dielectric behavior of manganese doped barium titanate-polyimide composites. Adv Polym

La doped barium titanate/polyimide nanocomposites: A study of the effect of La doping and investigation on thermal, mechanical and high dielectric properties

“…These peaks were appeared as a result of complete thermal imidization of nanocomposite thin films. Our previous research work showed the similar data for the pure polyimide thin film …”

“…The X‐ray diffractograms of BTL/PI nanocomposite thin films are displayed in Figure . Like pure polyimide, a hump was observed in all the prepared nanocomposite thin films at around 19° (2θ value). X‐ray diffraction pattern revealed that there was no any sharp peak for nanocomposite thin films, which implies that all the prepared films were amorphous in nature .…”

“…The calculated dielectric constant values for nanocomposite films are reported in Table . The values varied from 3.23 (for pure polyimide) to 25.05 (for 5 wt% BTL/PI) at 1 Hz frequency, this showed that nanocomposite films having much higher dielectric constant value than that of the pure polyimide. Dielectric constant values of all the prepared samples were almost constant in higher frequency region that mean the values were weak frequency dependent in this region.…”

“…Glass transition temperatures of the films are reported in Table . The Tg values were varied from 251 to 280 °C with the increase in 0–5 wt% of BTL ceramic respectively.…”

Synthesis, characterization, thermal, dynamic mechanical, and dielectric studies of Ba0.7Sr0.3TiO3/polystyrene composites

“…This region serves well for tunable microwave device applications due to the associated high dielectric constant and low losses . However, utilization of BST in miniaturized multilayer structures is not frequent due to high dielectric loss (tan δ) in microwave region and the brittleness and rigidity of the ceramic .…”