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      Permanent link:
      https://www.ias.ac.in/article/fulltext/boms/040/07/1497-1501

    • Keywords

       

      Microwave shielding; glass–ceramics; nucleating agent.

    • Abstract

       

      MgO−Al$_2$O$_3$−SiO$_2$ (MAS)-based glass–ceramic system was prepared using very-low-cost raw materials, i.e.,talc, calcined alumina and calcined china clay with titanium dioxide as a nucleating agent. Glass–ceramics were preparedby a two-step process. In the first step, raw materials were mixed in the required proportion and melted at 1450$^{\circ}$C followedby water quench into a glassy frit. In the second step, powdered glass frit was uniaxially dry pressed into pellets followedby sintering at 1200$^{\circ}$C for 3h. X-ray diffraction pattern of the sintered compact shows well-defined peaks of cordieritealong with some anorthite and magnesium titanium oxide. The microstructure study of sample shows the presence of crystallineand glassy phases. Permittivity and permeability measurements were performed in the microwave frequency range12.4–17 GHz. The permittivity value of 5.7–6.0 and the permeability value of $\sim$1 were obtained. The reflection and transmission measurements show that the material possesses a shielding effectiveness in the range 2–10 dB over the frequencyrange 12.4–17 GHz.

    • Author Affiliations

       

      PREETI KUMARI1 PANKAJ TRIPATHI1 OM PARKASH1 DEVENDRA KUMAR1

      1. Department of Ceramic Engineering, Indian Institute of Technology (Banaras Hindu University), Varanasi 221 005, India
    • Dates

       

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