57Fe NMR study of manganese ferrites

• Published in: Journal of magnetism and magnetic materials Vol. 320; no. 14; pp. e96 - e99
• Main Authors: Chlan, V., Procházka, V., Štěpánková, H., Sedlák, B., Novák, P., Šimša, Z., Brabers, V.A.M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-07-2008
• Subjects: Hyperfine interaction; Magnetic oxide; Manganese ferrite; NMR; Spinel; Manganese ferrite; NMR; Hyperfine interaction; Spinel; 75.25. + z; 75.50.Gg; Magnetic oxide; 76.60.−k
• ISSN: 0304-8853
• DOI: 10.1016/j.jmmm.2008.02.022

Magnetic properties of the manganese ferrites
Mn
x
Fe
3
-
x
O
4
are markedly influenced by the valence states of Mn and Fe ions and by their distribution between the octahedral and tetrahedral sublattices. Hyperfine methods are capable of providing useful information on these characteristics, which is difficult to obtain otherwise. In the present contribution the
Mn
x
Fe
3
-
x
O
4
(
0.52
<
x
<
1.80
)
cubic single crystals are studied by means of
57Fe nuclear magnetic resonance (NMR) at the liquid helium temperature. High quality samples and sensitive NMR equipment allowed to detect several well resolved
57Fe NMR spectral lines in the frequency range of 67–74
MHz in zero external magnetic field. In order to find out the location of iron nuclei from which the lines originate we applied external magnetic fields up to 1
T. This approach allows assignment of two spectral lines to iron nuclei in octahedral sublattice and one spectral line to irons in tetrahedral sublattice.