Phase transitions, dielectric, magnetic properties and valence of ions in AFe2/3W1/3O3±σ (A = Ba, Sr) multiferroic ceramics
Autor: | Stanislav P. Kubrin, Yu. V. Rusalev, L. A. Reznichenko, A.V. Nikolskii, Alexey T. Kozakov, V.V. Stashenko, L. A. Shilkina, A. V. Pavlenko, K.S. Petrosyan |
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Rok vydání: | 2018 |
Předmět: |
Phase transition
Materials science Mechanical Engineering Metals and Alloys Analytical chemistry 02 engineering and technology Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Ferroelectricity Tetragonal crystal system X-ray photoelectron spectroscopy Mechanics of Materials 0103 physical sciences Mössbauer spectroscopy Materials Chemistry Multiferroics 010306 general physics 0210 nano-technology Solid solution |
Zdroj: | Journal of Alloys and Compounds. 740:1037-1045 |
ISSN: | 0925-8388 |
Popis: | The polycrystal multiferroic samples of BaFe2/3W1/3O3 (BFWO) and SrFe2/3W1/3O3 (SFWO) are synthesized by solid solution reaction route followed by sintering. The samples are analyzed using the methods of X-ray diffraction (XRD), dielectric, Mossbauer and X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM). The XRD study reveals that BFWO possesses two crystal phases: cubic and hexagonal. SFWO is a single phase with a tetragonal symmetry. The VSM and Mossbauer spectroscopy show that both materials are ferrimagnets with magnetic phase transition temperatures TM ≈ 300 K for BFWO and TM ≈ 400 K for SFWO. The iron ions are in Fe3+ state. The XPS studies reveal the presence of the oxygen vacancies in the BFWO and SFWO samples which are responsible for the appearance of the tungsten ions with intermediate valences. BFWO is found to be paraelectric at room temperature. In the SFWO sample the phase transition from tetragonal (ferroelectric) to cubic (paraelectric) phase occurs in the range of 420 |
Databáze: | OpenAIRE |
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