Structural and multiferroic properties in double-layer Aurivillius phase Pb0.4Bi2.1La0.5Nb1.7Mn0.3O9 prepared by molten salt method

Tio Putra Wendari, Syukri Arief, Nandang Mufti, Andon Insani, Jacob Baas, Graeme R. Blake, [No Value] Zulhadjri*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

6 Citations (Scopus)

Abstract

A single-phase sample of the Aurivillius compound Pb0.4Bi2.1La0.5Nb1.7Mn0.3O9 was prepared by a molten salt method using K2SO4/Na2SO4 as the flux. The crystal structure, morphology, ferroelectric, and magnetic properties were investigated. Neutron powder diffraction data confirmed a non-centrosymmetric orthorhombic crystal structure with space group A21am and Pb/Bi disorder in the bismuth oxide blocks, Bi/Pb/La disorder on the perovskite A-site, and Nb/Mn disorder on the perovskite B-site. The morphology of the sample showed anisotropic plate-like grains as probed by scanning electron microscopy. The dielectric constant exhibits a transition peak between 600 K and 640 K that depends on frequency, indicating relaxor ferroelectric behavior. Electrical polarization versus applied field loops are unsaturated, with a remnant polarization of 0.43 μC/cm2 at 40 Hz under the maximum electrical field applied of 160 kV/cm. The ferroelectricity originates from the displacement of oxygen atoms in the BO6 octahedra, resulting in a polar structural distortion. Magnetic susceptibility measurements showed the presence of mixed Mn3+ and Mn4+, resulting in short-range ferromagnetic order via double exchange interactions below 33 K. The remnant magnetization (Mr) is 0.01 emu/g at 5 K. This mixed valence of Mn cations is mainly responsible for the high electrical conductivity. Thus, Pb0.4Bi2.1La0.5Nb1.7Mn0.3O9 exhibits coexisting ferroelectric and ferromagnetic properties.

Original languageEnglish
Article number153145
Number of pages6
JournalJournal of Alloys and Compounds
Volume820
DOIs
Publication statusPublished - 15-Apr-2020

Keywords

  • Double-layer Aurivillius phase
  • Molten salt method
  • Cation disorder
  • Multiferroic
  • Relaxor-ferroelectric behavior
  • Ferromagnetic interactions
  • ELECTRICAL-PROPERTIES
  • CATION DISORDER

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