Details

Autor(en) / Beteiligte

• Maczka, M
• Pietraszko, A
• Saraiva, G D
• Souza Filho, A G
• Paraguassu, W
• Lemos, V
• Perottoni, C A
• Gallas, M R
• Freire, P T C
• Tomaszewski, P E
• Melo, F E A
• Mendes Filho, J
• Hanuza, J

Titel

High pressure effects on the structural and vibrational properties of antiferromagnetic KFe(MoO4)2

Ist Teil von

• Journal of physics. Condensed matter, 2005-10, Vol.17 (39), p.6285-6300

Ort / Verlag

Bristol: IOP Publishing

Erscheinungsjahr

2005

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The crystal structure of the paraelastic phase of KFe(MoO4)2 at 360K was reinvestigated and high pressure Raman scattering experiments were performed on this material. The studies indicated that this molybdate crystallizes in the &Pbar 3m1; structure above 312K. At room temperature the structure is monoclinic and it transforms under pressure into &Pbar 3m1;, &Pbar 3c1; and low symmetry phases at 0.25, 1.3 and 1.6GPa, respectively. The phase transitions observed at 0.25 and 1.6GPa are irreversible whereas the 1.3GPa transition is reversible. The lattice dynamics calculations performed for the &Pbar 3m1; phase allowed us to obtain an assignment of observed modes and helped us to obtain insight into the mechanism driving the structural changes occurring in this material. The x-ray study of the highest pressure phase, recovered during the decompression experiment, shows that the crystal structure of this phase is monoclinic or triclinic. When this phase is subjected to heat treatment at 673K, it either transforms into another phase or decomposes.