Details

Autor(en) / Beteiligte

• Mączka, M.
• Almeida da Silva, T.
• Paraguassu, W.
• Pereira da Silva, K.

Titel

Raman scattering studies of pressure-induced phase transitions in perovskite formates [(CH3)2NH2][Mg(HCOO)3] and [(CH3)2NH2][Cd(HCOO)3]

Ist Teil von

• Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, 2016-03, Vol.156, p.112-117

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2016

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Pressure-dependent Raman studies were preformed on two dimethylammonium metal formates, [(CH3)2NH2][Mg(HCOO)3] (DMMg) and [(CH3)2NH2][Cd(HCOO)3] (DMCd). They revealed three pressure-induced transitions in the DMMg near 2.2, 4.0 and 5.6GPa. These transitions are associated with significant distortion of the anionic framework and the phase transition at 5.6GPa has also great impact on the DMA+ cation. The DMCd undergoes two pressure-induced phase transitions. The first transition occurred between 1.2 and 2.0GPa and the second one near 3.6GPa. The first transition leads to subtle structural changes associated with distortion of anionic framework and the later leads to significant distortion of the framework. In contrast to the DMMg, the third transition associated with distortion of DMA+ cation is not observed for the DMCd up to 7.8GPa. This difference can be most likely associated with larger volume of the cavity occupied by DMA+ cation in the DMCd and thus weaker interactions between anionic framework and DMA+ cations. Pressure-dependent Raman studies were performed on [(CH3)2NH2][Mg(HCOO)3] and [(CH3)2NH2][Cd(HCOO)3]. These studies revealed three and two pressure-induced phase transitions in the Mg- and Cd-compound, respectively. Structural changes associated with these transitions are discussed. [Display omitted] •High-pressure Raman studies were performed on [(CH3)2NH2][M(HCOO)3] (M=Mg, Cd)•Mg-compound exhibits three phase transitions and 2.2, 4.0 and 5.6GPa•Cd-compound exhibits two phase transitions near 1.2–2.0GPa and 3.6GPa•All transitions lead to distortion of the framework and decrease of symmetry•The transition at 5.6GPa in DMMg strongly affects the DMA+ cations