Electronic structure and multiferroic properties of (Y, Mn)-doped barium hexaferrite compounds

• Published in: Journal of alloys and compounds Vol. 867; p. 158794
• Main Authors: Thang, P.D., Tiep, N.H., Ho, T.A., Co, N.D., Hong, N.T.M., Dong, Q.V., Lee, B.W., Phan, T.L., Dang, N.T., Khan, D.T., Yang, D.S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25-06-2021; Elsevier BV
• Subjects: Absorption spectra; Barium hexaferrite; Chemical equilibrium; Coercivity; Crystal structure; Diffraction patterns; Electric fields; Electronic structure; Electronic structures; Ferroelectricity; Hexaferrite compounds; Hysteresis loops; Ions; Jahn-Teller effect; Lattice parameters; Leakage current; Magnetic properties; Multiferroic properties; Oxidation; Polarization; Raman spectra; X ray absorption; Electronic structures; Hexaferrite compounds; Multiferroic properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.158794

•Electronic structure and multiferroic properties of (Y, Mn)-doped BaM compounds.•Enhanced Jahn-Teller distortions as increasing Mn-doping concentration.•Chemical shift of Mn2+→ Mn3+ and replacement of Mn2+,3+ for Fe3+ in BaM compounds.•Hard magnetic and a change in ferroelectric properties of BaM compounds.
We have systematically studied the crystal and electronic structures and the magnetic and electrical polarization properties of polycrystalline Ba0.95Y0.05Fe12−xMnxO19 (denoted as BaYFe12−xMnxO19) compounds with x = 0–2. The analyzes of X-ray diffraction patterns and Raman scattering spectra indicated their single phase in the M-type hexaferrite structure. With increasing x, the lattice constant a slightly increased while c decreased, which related to the Jahn-Teller effect. Though an increase of x reduced gradually magnetization in a range of 23–32 emu/g, the coercive force increased from 3.3 kOe for x = 0 to about 4 kOe for x = 0.5–2. The study of the electrical polarization properties proved the dependence of the shape of electric hysteresis loops on x and applied electric field. The samples with x = 0 and 0.5 exhibit a weak ferroelectricity with the maximum polarization of ~0.11 μC/cm2 for x = 0, and of ~0.06 μC/cm2 for x = 0.5. Meanwhile, the other samples showed nearly circular hysteresis loops, which are characteristic of conductive materials. Detailed investigations indicated an increase in leakage current when x increased. All of such phenomena are tightly related to the chemical shift of Mn2+ → Mn3+ and the replacement of Mn2+,3+ for Fe3+ in BaYFe12−xMnxO19. These oxidation states and the chemical shift of Mn have been confirmed upon analyzing X-ray absorption spectra.