Spectral investigation of the phase-transition behavior in (DOEO)4HgBr4·TCE salt
| Autor: | Alicja Gąsecka, Alexander I. Kotov, S. Waplak, Andrzej Łapiński, A. Ostrowski, Andrzej Graja |
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| Rok vydání: | 2012 |
| Předmět: |
Phase transition
Condensed matter physics Chemistry Organic Chemistry Analytical chemistry Infrared spectroscopy Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention Inorganic Chemistry Metal Orders of magnitude (specific energy) Electrical resistivity and conductivity Normal mode law visual_art visual_art.visual_art_medium Electrical and Electronic Engineering Physical and Theoretical Chemistry Electron paramagnetic resonance Spectroscopy Line (formation) |
| Zdroj: | Optical Materials. 34:1651-1655 |
| ISSN: | 0925-3467 |
| DOI: | 10.1016/j.optmat.2012.03.012 |
| Popis: | Room temperature electrical conductivity of (DOEO)4HgBr4·TCE single crystals measured along the a-direction is of the order of 1 S/cm, while perpendicularly to this direction is almost five orders of magnitude smaller. Besides, on cooling the resistivity increases until a maximum reached around 140 K, becomes metallic in the lower temperature, and finally undergoes an insulating transition around 50 K. To add some new observations and explain these interesting properties of the salt we present extended investigations of its spectral properties. In this paper, we discuss the temperature EPR studies of (DOEO)4HgBr4·TCE salt as well as the evolution of its IR spectra vs. temperature. In particular, the analysis of changes of selected normal modes wavenumbers is discussed. Significant changes of EPR shape and characteristic line splitting were observed. It was shown that possible explanation for the peculiar resistivity of (DOEO)4HgBr4·TCE salt observed at about 140 K relates to the disordering of anions and ethylene groups. Their partial ordering can lead to the observed metallic behavior but cannot prevent further localization at lower temperature. |
| Databáze: | OpenAIRE |
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