Evidence of two competitive phenomena involved in the phase transition process at 144 K in K<sub>2</sub>ZnCl<sub>4</sub> from x-ray diffraction and DSC experiments
A Hedoux; Y Guinet; F X Leduc; M More; M Foulon; F Danede; G Odou; A Hedoux; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; Y Guinet; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; F X Leduc; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; M More; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; M Foulon; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; F Danede; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France; G Odou; Lab. de Dynamique et Structure des Mater. Moleculaires, Lille I Univ., Villeneuve d'Ascq, France
Журнал:
Journal of Physics: Condensed Matter
Дата:
1995-09-25
Аннотация:
Differential scanning calorimetry and x-ray diffraction experiments performed in K<sub>2</sub>ZnCl<sub>4</sub> have clearly revealed that two phenomena are involved in the phase transition process at 148 K. The first one corresponds to a slow reorganization of the tetrahedron configuration responsible for the development of a diffuse scattering localized on (a*+b*)/2 points of the reciprocal space. The second phenomenon corresponds to the growth of the (a*+b*)/2 superstructure phase. A very new feature results from observation of a competitive character between these two phenomena. It is shown that the kinetic behaviour of the first phenomenon and its possible correlation to the crystal growth defects are certainly involved in the phase transition process at 148 K.
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