Faculty of Physics
M.V.Lomonosov Moscow State University
Regular Article

# New method for determining parameters of potential well of noncentral atoms using exafs spectroscopy

## A.I. Lebedev, I.A. Sluchinskaya

### Moscow University Physics Bulletin 2005. 60. N 6. P. 58

• Article
Annotation

A new method to determine parameters of a three-dimensional multiwell potential of noncentral atoms from EXAFS data has been proposed. The main features of this approach are the series expansion of a three-dimensional potential in a cluster in displacement degrees with allowance for constraints imposed by lattice-node symmetry and the exact three-dimensional integration of the distribution function in calculation of EXAFS spectra. Within the framework of this approach, parameters of a multiwell potential were estimated for the first time in classical approximation for a Ge atom in solid solution Sn$_{1-x}$Ge$_x$Te ($77\le T\le300$ K, $x\ge0.4$). It is shown that the anharmonic part of the potential is strongly anisotropic and that by its type a ferroelectric phase transition in Sn$_{1-x}$Ge$_x$Te is intermediate between the displacement and order—disorder transitions.

Rissian citation:
А.И. Лебедев, И.А. Случинская.
Вестн. Моск. ун-та. Сер. 3. Физ. Астрон. 2005. № 6. С. 46.
Authors
A.I. Lebedev, I.A. Sluchinskaya
Department of Semiconductor Physics, Faculty of Physics, Moscow State University, Leninskie Gory, Moscow, 119992, Russia

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