Электронный каталог

Статья

Secu, M.
Structural and Magneto-Optical Investigations of Citrate Sol–Gel Derived Barium Hexaferrite Nanocrystalline Powder / M.Secu, V.Turchenko, [et al.] // Journal of Alloys and Compounds [Electronic resource]. – 2024. – Vol. 983. – P. 173897. – URL: https://doi.org/10.1016/j.jallcom.2024.173897. – Bibliogr.: 41.

Magneto-optical measurements enable the identification of Fe*2*+ and Fe*3*+ in the R and S blocks of BaFe&sub(12)O&sub(19) M-hexaferrite powder obtained by sol-gel processing, followed by thermal annealing at 900 C for 3 hours. The ferromagnetic phase is evidenced by the spin-majority configuration (Fe*3*+) due to their unpaired electrons between d-d orbitals, while the Fe*2*+ in the low spin possesses diamagnetic behavior strongly dependent on the surrounded crystal field. Additionally, the irradiation with gamma rays changes the ratio between Fe*2*+/Fe*3*+, mainly on the surface of BaFe&sub(12)O&sub(19) nanocrystals. These changes were confirmed by X-ray Photoelectron Spectroscopy measurements, in which the concentration of Fe*2*+ increased from 69% to 82%, while the one of Fe*3*+ decreased from 31% to 18%. he thermoluminescent measurements reveal the same changes of Fe*3*+ in Fe*2*+ by electron capturing during irradiation, which is released as a red emission after recombination processes. The changes are explained by the increasing of some Fe-O bonds along the c-axis, mainly due to breaking a part of these bonds. The X-ray analysis confirms the changing of the parameters for the BaFe&sub(12)O&sub(19) hexagonal structure



Спец.(статьи,препринты) = С 332.8 - Синхротронное излучение. Лазеры на свободных электронах. Получение и использование рентгеновских лучей
ОИЯИ = ОИЯИ (JINR)2024
Бюллетени = 25/024