DocumentCode
1077104
Title
Spin orientation of hematite (α-Fe2O3) nanoparticles during the Morin transition
Author
Gee, S.-H. ; Hong, Y.-K. ; Sur, J.C. ; Erickson, D.W. ; Park, M.H. ; Jeffers, F.
Author_Institution
Dept. of Mater. Sci. & Eng., Univ. of Idaho, Moscow, ID, USA
Volume
40
Issue
4
fYear
2004
fDate
7/1/2004 12:00:00 AM
Firstpage
2691
Lastpage
2693
Abstract
We have synthesized 40-nm-sized hematite particles by the forced hydrolysis of acid Fe3+ solution to investigate the change in spin direction during the Morin transition. Mössbauer spectra were obtained at various temperatures ranging from 4.3 to 300 K. The Morin temperature (TM) was found to be 220 K, which is lower than 263 K of bulk hematite. Fe3+ spins in the 40-nm-sized hematite particle flip from 90° to 28° with respect to the c-axis of hexagonal structure during the Morin transition, which corresponds to the [110] direction of rhombohedral structure. This is not in agreement with the spin flip from 90° to 0° observed in bulk hematite or sub- and micron-sized particles at TM.
Keywords
Morin temperature; Mossbauer effect; iron compounds; minerals; nanoparticles; spin dynamics; α-Fe2O3; 220 K; 40 nm; Fe2O3; Morin temperature; Morin transition; Mossbauer spectra; acid Fe+3 solution; hematite particles; hexagonal structure; hydrolysis; nanoparticles; rhombohedral structure; spin direction change; spin flip; spin orientation; Antiferromagnetic materials; Containers; Helium; Iron; Lattices; Magnetic properties; Magnetic separation; Nanoparticles; Shape; Temperature distribution; Hematite; Mössbauer spectrum; nanoparticles; spin-flip;
fLanguage
English
Journal_Title
Magnetics, IEEE Transactions on
Publisher
ieee
ISSN
0018-9464
Type
jour
DOI
10.1109/TMAG.2004.832253
Filename
1325611
Link To Document