• Abdul Manan

      Articles written in Bulletin of Materials Science

    • Synthesis and microwave dielectric properties of Ca substituted SrLa4Ti4.93Zr0.07O17 ceramics

      Abdul Manan Ibrahim Qazi

      More Details Abstract Fulltext PDF

      Microwave dielectric ceramics in Sr1-𝑥Ca𝑥La4Ti4.93Zr0.07O17 (0 ≤ 𝑥 ≤ 0.5) composition series were processed via a solid-state sintering rout. X-ray diffraction revealed single phase ceramics. Ca substitutions for Sr tuned 𝜏f towards zero with increased 𝑄u𝑓o values. In the present study, 𝜖r∼ 55, 𝑄u𝑓o ∼ 11960 GHz and 𝜏𝑓∼ 5.2 ppm/°C were achieved for the composition with 𝑥 = 0.3.

    • Improvement in the microwave dielectric properties of SrCa4Nb4TiO17 ceramics by Ba substitution

      Abdul Manan Yaseen Iqbal

      More Details Abstract Fulltext PDF

      Microwave dielectric ceramics in the Sr1–𝑥Ba𝑥Ca4Nb4TiO17 (0 ≤ 𝑥 ≤ 0.75) composition series were fabricated via a solid-state mixed oxide route. All the compositions formed single phase in Sr1–𝑥Ba𝑥Ca4Nb4TiO17 (0 ≤ 𝑥 ≤ 0.75) solid solutions within the detection limit of in-house X-ray diffraction (XRD). The sintered microstructure of these ceramics comprised densely packed elongated and plate-like grains. The dielectric properties varied linearly with 𝑥. Relative permittivity (𝜀r) increased from 47.2 to 54.5, unloaded quality factor multiplying the resonant frequency (𝑄u 𝑓o) decreased from 11,984 to 9345 GHz and temperature coefficient of resonant frequency (𝜏f) increased from –78.6 to 20 ppm/°C with an increase in x from 0 to 0.75. In the present study, 𝜀r ≈ 51.6, 𝑄u 𝑓o ≈ 10,160 GHz (5.37 GHz) and 𝜏f ≈ –13.5 ppm/°C were achieved for Sr0.5Ba0.5Ca4Nb4TiO17 (𝑥 = 0.5) ceramics.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

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