Tunable microwave absorption of switchable complexes operating near room temperature.

Autor: Kucheriv OI; Department of Chemistry, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine illia.guralskyi@univ.kiev.ua., Oliynyk VV; Department of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine., Zagorodnii VV; Department of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine., Launets VL; Department of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine., Penkivska OV; Department of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine., Fritsky IO; Department of Chemistry, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine illia.guralskyi@univ.kiev.ua., Gural'skiy IA; Department of Chemistry, Taras Shevchenko National University of Kyiv 64 Volodymyrska St. Kyiv 01601 Ukraine illia.guralskyi@univ.kiev.ua.
Jazyk: angličtina
Zdroj: RSC advances [RSC Adv] 2020 Jun 05; Vol. 10 (36), pp. 21621-21628. Date of Electronic Publication: 2020 Jun 05 (Print Publication: 2020).
DOI: 10.1039/d0ra02236e
Abstrakt: Materials that are able to switch microwave radiation are strongly desired for their potential applications in electronic devices. In this paper, we show the spin-dependant interaction of spin-crossover materials with microwave radiation, namely, the ability of coordination compounds [Fe(NH 2 trz) 3 ]Br 2 and [Fe(NH 2 trz) 3 ](NO 3 ) 2 that undergo a cooperative spin transition between low-spin and high-spin states to operate as thermoswitchable microwave absorbers. The characteristics of the microwave reflection and transmission of these spin-crossover complexes were investigated at variable temperatures. The evolution of both the transmission and reflection spectra in the 26-37 GHz frequency band within the temperature range of spin crossover showed significant differences in the interaction of microwave radiation with the high-spin and low-spin forms of the compounds. The microwave transmission coefficient shows a notable decrease upon transition to the high-spin state, while the reflection coefficient can be both increased or decreased on the characteristic frequencies during the spin transition. The different microwave absorbing properties of the low-spin and high-spin forms are found to be associated with a notable microwave permittivity change upon spin crossover. The switchable microwave reflection/transmission correlates well with the transition characteristics found in the optical and differential scanning calorimetry measurements. These results widen the spectroscopic range in which spin-crossover materials can be applied and contribute to the creation of a preliminary database of the microwave absorbing properties of spin-crossover complexes.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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