Structure and dynamics of octamethyl-ethinyl-ferrocene: an organometallic rotator phase

Autor:	U. van Bürck, H. Franz, K. Messel, Robert E. Dinnebier, T. Asthalter, E. Schreier
Rok vydání:	2003
Předmět:	Phase transition Mössbauer effect General Chemistry Calorimetry Atmospheric temperature range Photon energy Condensed Matter Physics Crystallography chemistry.chemical_compound Ferrocene chemistry Chemical physics Phase (matter) General Materials Science Powder diffraction
Zdroj:	Journal of Physics and Chemistry of Solids. 64:677-684
ISSN:	0022-3697
DOI:	10.1016/s0022-3697(02)00376-1
Popis:	The onset of dynamics and the structural changes of octamethyl–ethinyl-ferrocene around a solid–solid phase transition at 248 K have been investigated using the novel technique of quasielastic nuclear forward scattering (QNFS) in a temperature range between 61 and 257 K at a photon energy of 14.413 keV, as well as X-ray powder diffraction at various energies. A pronounced hysteresis for both the dynamical and the structural properties is observed and confirmed by differential-scanning calorimetry. We assign the observed phenomena to a first-order transition from a low-symmetry low-temperature phase to a high-symmetry high-temperature plastically crystalline phase with nearly cubic symmetry. Possible mechanisms for this transition are discussed in the light of our results.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ef08a9ec7d52c96702f038bb58b4ebcf https://doi.org/10.1016/s0022-3697(02)00376-1 Zobrazit plný text záznamu Full Text from ScienceDirect