Influence of Ca2+ doping on structural, dielectric and magnetic properties of Sr2MgCo2-xCaxFe24O41 for potential antenna applications

K. Praveena, K. Sadhana, R. Sandhya, S. R. Murthy, Hsiang Lin Liu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Z-type hexaferrites Sr2MgCo2-xCaxFe24O41 of stoichiometric composition where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 were prepared by sol-gel method. The obtained nanopowders were sintered at 950 °C/4 h using conventional sintering method. The samples were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Phase analysis of Ca-doped Sr2MgCo2-xCaxFe24O41 powders revealed pure Z-type hexaferrites phase. The room temperature dielectric and magnetic properties (ε′, ε″, μ′ and μ″) were studied using RF impedance analyzer in the frequency range of 1 MHz to 1.8 GHz. The dielectric responses of these compounds are found to be frequency dependent and show the frequency stability upto 1.4 GHz. The relaxation-type dielectric behavior is dominating in the low frequency region and resonance-type dielectric behavior is found to be dominating above 109 Hz. It was inferred that the permeability was sensitively controlled by the substitution of Ca2+. The coercivity (Hc) increased gradually with an increase of calcium content. Frequency variation of AC conductivity is explained in terms of hopping of electrons between Fe2+ and Fe3+. Since loss tangent was kept low with the frequency ranging from 1 MHz to 1.4 GHz, such magneto-dielectric material could be used in this frequency range for antenna miniaturization.

Original languageEnglish
Pages (from-to)8869-8877
Number of pages9
JournalCeramics International
Volume42
Issue number7
DOIs
Publication statusPublished - 2016 May 15

Keywords

  • Dielectric properties
  • Low loss
  • Low temperature sintering
  • Magnetic properties
  • Sol-gel route
  • Z-type hexaferrite

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry

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