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キーワード:
high pressure; X-ray powder diffraction; crystal structure; dipotassium sulfide
要旨:
The high-pressure behaviour of dipotassium sulfide K2S with the
antifluorite structure (Fm (3) over barm, Z = 4) has been
studied up to 23.0 GPa by in situ synchrotron angle-dispersive
X-ray powder diffraction in a diamond anvil cell at room
temperature. There occurs a transformation into a distorted
Ni2In-type structure (Pmma, Z = 4) at about 6 GPa upon
compression. A mixture of several phases is observed at lower
pressures. Unlike in the case of pressure-induced modifications
of Li2S and Na2S, none of them is of the anticotunnite-type
(Pnma, Z = 4). The Ni2In-related structure,of K2S is compared
with the cationic arrays found in different polymorphs of K2SO3
and K2SO4. (C) 2002 Editions scientifiques et medicales
Elsevier SAS. All rights reserved.
