hide
Free keywords:
-
Abstract:
A reversible phase transition was found for iron-deficient TlFe2-xSe2 (x
approximate to 0.4) and investigated on single crystals using high
temperature synchrotron radiation X-ray diffraction. Full data sets have
been collected at room temperature and at 200 degrees C to evaluate the
structures. The high-temperature form (space group I4/mmm, lattice
parameters a = 3.8919(3) angstrom, c = 14.027(3) angstrom) shows
complete statistical disorder of iron positions and vacancies in a
ThCr2Si2 type structure. The low-temperature form corresponds to a root
5 x root 5 superstructure of the ThCr2Si2 type (I4/m, a = 8.6966(2)
angstrom, c = 14.009(9) angstrom) and shows partial ordering of iron
positions and vacancies. A group-subgroup relation can be compiled
between both structures. (c) 2013 WILEY-VCH Verlag GmbH & Co. KGaA,
Weinheim