ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The properties of fine particles of α-Fe2O3 (sample A), and α-Fe2O3 coated with cobalt (sample B) and adsorbed with pyridine (sample C) have been investigated by means of magnetic measurements, Mössbauer spectra and x-ray photoelectron spectroscopy (XPS). The size of these fine particles is about 500 A(ring). The Morin transition temperatures Tm for samples A, B, and C are 191, 〈80, and 224 K, respectively. The Mössbauer spectra of the samples were measured in a temperature range from 80 to 300 K and the angles between 〈111〉 axis and the spin of iron ions for these samples have been calculated from these spectra. The XPS results show that the Fe 2p and 3d peaks of sample C shift to lower energy regions compared with those of sample A. It seems to be that some electrons may move from pyridine molecules to the iron atoms in sample C. The reasons for the Tm change of samples B and C were discussed on the basis of the experimental results.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.350102
