Results in Physics (Apr 2024)

Ferrimagnetic transition, relaxor ferroelectric and optical properties in tungsten bronze Ba6MnNb9O30 ceramics

  • X.Z. Zuo,
  • Y.F. Zheng,
  • B.G. Guan,
  • W. Dong,
  • Z.Z. Hui,
  • J. Yang,
  • X.B. Zhu,
  • J.M. Dai

Journal volume & issue
Vol. 59
p. 107586

Abstract

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The structural, magnetic, ferroelectric, dielectric and optical properties of Ba6MnNb9O30 (BMNO) and Ba6Mn0.5Co0.5Nb9O30 (BMCNO) ceramics were investigated. The samples can be indexed by a tetragonal lattice and the space group of P4bm with the presence of a tiny amount of impurity phase Ba1.04NbO3. The sample BMNO undergoes a short-range ferrimagnetic-like transition at 43 K originating from the spin canting of the antiferromagnetic coupling between the adjacent Mn2+ and Mn3+ based sublattices via the Dzyaloshinskii-Moriya interaction, whereas the sample BMCNO exhibits a local short-range antiferromagnetic state with the presence of weak ferromagnetic ordering. Both samples show the relaxor ferroelectric nature. The sample BMCNO possesses a superior energy storage property with a total energy density of 1.58 J/cm3 and a conversion efficiency of 74.5 %, which can be mainly ascribed to the improved densification and the reduced oxygen vacancies. Two different dielectric relaxations are discussed in term of the Vogel-Fulcher law. In addition, all samples have two different absorption edges and the optical band gaps are determined to be about 2.2 eV and 2.8 eV.

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