| Numéro |
J. Phys. Colloques
Volume 47, Numéro C8, Décembre 1986
EXAFS and Near Edge Structure IV
|
|
|---|---|---|
| Page(s) | C8-733 - C8-735 | |
| DOI | https://doi.org/10.1051/jphyscol:19868138 | |
EXAFS and Near Edge Structure IV
J. Phys. Colloques 47 (1986) C8-733-C8-735
DOI: 10.1051/jphyscol:19868138
1 Institute of Physical Chemistry, University of Hamburg, Bundestrasse 45, D-2000 Hamburg 13, F.R.G.
2 Haldor Topsoe Research Laboratories, DK-2800 Lyngby
J. Phys. Colloques 47 (1986) C8-733-C8-735
DOI: 10.1051/jphyscol:19868138
INVESTIGATION OF THE DOUBLE-PHASE TRANSITION OF Tm3Fe5O12, BY EXAFS SPECTROSCOPY
H. BEUTHIEN1, D.v. AHLFTEN1, W. GIRNUS1, A. TORKLER1, W. GUNSSER1 et W. NIEMANN21 Institute of Physical Chemistry, University of Hamburg, Bundestrasse 45, D-2000 Hamburg 13, F.R.G.
2 Haldor Topsoe Research Laboratories, DK-2800 Lyngby
Abstract
Coprecipitated Thulium-iron hydroxides with garnet stoichiometry (TmIG) have been investigated at several annealing temperatures (from 333 K to 1453 K) using differential thermal analysis (DTA), x-ray diffraction (XRD) and EXAFS at the LIII edge of Tm. Two phase transitions at 1043 K and 1091 K are observed by DTA. XRD proves that the crystallization of TmIG is completed at 1091 K. The analysis of the nearest neighbour shell of the EXAFS data shows the presence of three temperature regions separated by the two phase transitions. The different oxide geometries in these regions are elucidated by EXAFS fits.