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| VOLUME 83 (2006) | ISSUE 1 | PAGE 41 |
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Equation of State and High Pressure Irreversible Amorphization in Y3Fe5O12
A. G. Gavriliuk
 , V. V. Struzhkin+, I. S. Lyubutin , M. I. Eremets , I. A. Trojan*, V. V. Artemov+Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington DC 20015 *Institute for High Pressure Physics RAS, 142190 Troitsk, Moscow reg., Russia Institute of Crystallography RAS, 119333 Moscow, RussiaMax-Planck Institut fur Chemie, 55020 Mainz, Germany
PACS: 61.50.Ks, 64.30.+t, 71.30.+h, 81.40.Vw
Abstract
The change of crystal structure in the yttrium iron garnet Y3Fe5O12 was studied at room temperature at high pressures up to  GPa by the X-ray diffraction technique in diamond anvil cells. At
the pressure about  GPa the drastic change in the X-ray diffraction
pattern was observed indicating a transition into an amorphous-like state. At
the pressure increase the bulk modulus of YIG was found to be  GPa.
It was also found that the amorphous state was retained after decompression
down to ambient pressure. From the shape of X-ray patterns in "amorphous"
phase, it was concluded that the local atomic structure consists of
iron-oxygen FeO6 octahedral complexes with disordered orientations of
local axis and of the randomly arranged others ions fragments with the
overall Y3Fe5O12 composition. For amorphous phase it was evaluated
that the bulk modulus of FeO6 octahedral complexes is about 260 GPa.
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