Электронный каталог

Статья

Yao, Y.
Correlation of the Chemical Composition, Phase Content, Structural Characteristics and Magnetic Properties of the Bi-Substituted M-Type Hexaferrites / Y.Yao, V.A.Turchenko, [et al.] // Ceramics International [Electronic resource]. – 2023. – Vol. 49, No. 22, Pt. B. – P.37009-37016. – URL: https://doi.org/10.1016/j.ceramint.2023.09.033. – Bibliogr.:34.

Bi-substituted M-type hexaferrites, BaFe&sub(12-x)Bi&sub(x)O&sub(19) (0.1 ≤ x ≤ 1.2), or Bi-BaM, were produced by the solid-state reactions. The correlation between the phase content, chemical composition, crystal structure features, and peculiarities of the magnetic properties of Bi-BaM was established using XRD (X-ray diffraction), SEM (scanning electron microscopy), and VSM (vibrational sample magnetometry). XRD phase analysis made it possible to establish the limit of substitution of Fe&sup(3+) ions by Bi&sup(3+) ions. It was shown that at a low substitution level (x ≤ 0.3), no impurity phases were detected, and the samples are characterized by a single-phase state with the space group (SG) P63/mmc. As the degree of substitution (x ≥ 0.6) increases, the formation of impurity phases was observed, which can be explained by the difficulties of ion diffusion in the process of solid-phase synthesis as well as the formation of defects in the magnetoplumbite structure due to the large ionic radius of Bi&sup(3+). As impurity phases in the studied compositions (x ≥ 0.6) the following were noted: BiFeO&sub(3) (SG: Pnma); BiO&sub(2) (SG: Fm-3m); BaBi&sub(2)O&sub(6) (SG: R-3); and Ba&sub(0.5)Bi&sub(1.5)O&sub(2.16) (SG: Im-3m). The content of the main phase (SG: P6&sub(3)/mmc) decreases from 95.11 to 88.27 vol% with an increase in x from 0.6 to 1.2, respectively. Analysis of SEM images showed the growth of particles up to 10 μm, depending on the concentration of bismuth oxide during hexaferrite synthase. The Bi-BaM magnetic characteristics were examined using VSM in the range of 3 T at 300 K. Due to the magnetic structure's frustration, with increased x a decrease in saturation magnetization (M&sub(s)) was found. There were two concentration diapasons with different speeds of M&sub(s) decrease. In the first diapason, the main contribution belong to the magnetic structure frustration in the frame of the main phase (P6&sub(3)/mmc) due to the long-range Fe-O-Fe exchange interaction weakening (under Bi substitution). In the second diapason, the main contribution belong to the impurity phase formation and decrease of the main magnetic phase concentration in samples.



ОИЯИ = ОИЯИ (JINR)2023
Спец.(статьи,препринты) = С 332.8 - Синхротронное излучение. Лазеры на свободных электронах. Получение и использование рентгеновских лучей
Бюллетени = 11/024