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Updated: Apr 15, 2026
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Temperature-dependent studies of [(CH3)2NH2][Fe(III)M(II)(HCOO)6] frameworks (M(II) = Fe and Mg): structural,
Aneta Ciupa1, Mirosław Mączka, Anna Gągor
1Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Box 1410, 50-950 Wrocław 2, Poland. m.maczka@int.pan.wroc.pl.
Abstract:
Novel heterometallic formate [(CH3)2NH2][Fe(III)Mg(II)(HCOO)6] (DMFeMg) was prepared and characterized by single crystal X-ray diffraction, DSC, dielectric, magnetic susceptibility, Raman and IR methods. We also report thermal, Raman and IR studies of the known compound [(CH3)2NH2][Fe(III)Fe(II)(HCOO)6] (DMFeFe). DMFeMg crystallizes in the niccolite structure (P3[combining macron]1c space group). In contrast to the known DMFeFe, [(CH3)2NH2][Fe(III)Mn(II)(HCOO)6] (DMFeMn) and [(CH3)2NH2][Fe(III)Co(II)(HCOO)6] (DMFeCo) formates, the metal ions in DMFeMg are distributed statistically over the two available octahedral sites. Temperature-dependent studies show that whereas DMFeFe exhibits an order-disorder phase transition at 151.8 K upon cooling, freezing-in of re-orientational motions of DMA(+) cations does not lead to any structural phase transition in DMFeMg. We discuss the origin of this difference. The low-temperature studies also show that DMFeMg orders magnetically at TC = 13.5(5) K and the shape of M(T) measured in the field-cooling regime suggests ferromagnetic character of the ordering.
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