• Articles | Статьи

A Mössbauer study of pentavalent iron in a vanadium(V) oxide matrix

Mossbauer absorption spectra of iron-doped V2O5.

A Mössbauer study of pentavalent iron in a vanadium(V) oxide matrix. Dedushenko S.K., Perfiliev Y.D., Tcheboukov D.E., Pankratov D.A., Kiselev Y.M. //Mendeleev Communications. 1999. V. 9. № 5. P. 211-212Search the full text below. Ищи полный текст ниже.

The formation of iron in the 5+ oxidation state was observed in iron-doped vanadium(V) oxide; this state is characterised by a singlet with the isomer shift δ = -0.56 ± 0.01 mm·s-1 relative to α-iron in the Mössbauer spectrum at room temperature.

Подробнее...

Печать E-mail

Electron Paramagnetic Resonance Of Ferrite Nanoparticles

EPR spectra of Fe2O3 nanoparticles at different temperature. DH is the peak-to-peak linewidth, A is the EPR signal amplitude. It is presumed that S1 is the superparamagnetic signal (g=2.12) from the g-Fe2O3 phase, S2 is the paramagnetic EPR signal (g=2.02) from magnetically isolated centers in g-Fe2O3, S3 is the rhombic symmetry signal (g=4.3) from the a-Fe2O3 phase.

Electron Paramagnetic Resonance Of Ferrite Nanoparticles. Koksharov Yu.A., Pankratov D.A., Gubin S.P., Kosobudsky I.D., Beltran M., Khodorkovsky Y., Tishin A.M. //Journal of Applied Physics. 2001. V. 89. № 4. P. 2293-2298Search the full text below. Ищи полный текст ниже.

Three types of iron-based oxide nanoparticles (weight compositions Fe2O3, BaFe2O4, and BaFe12O19) embedded in a polyethylene matrix are studied using the electron paramagnetic resonance technique. All nanoparticles are found to be multiphase. Thermal variations of electron paramagnetic resonance spectra reveal the presence of two phases in the Fe2O3 nanoparticles. One such phase undergoes an antiferromagnetic-like transition near 6 K. Nanoparticles of BaFe2O4 demonstrate a resonance anomaly near 125 K that could indicate the presence of a magnetic phase. Reduced magnetic anisotropy in BaFe12O19 nanoparticles may be related to either structural imperfection or particle smallness (effective diameter of less than 10 nm). Our data clearly show that low temperature experiments are desirable for the correct identification of nanoparticles by means of the elecstron paramagnetic resonance technique.

Подробнее...

Печать E-mail

Materials on the same topic | Материалы по этой же теме

Рейтинг@Mail.ru

http://www.youtube.com/RuRedOx