Evidence of Cooperative Effects for the Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> Spin Crossover Molecular Complex in Polyaniline Plus Iron Magnetite
oleh: Wai Kiat Chin, Binny Tamang, M. Zaid Zaz, Arjun Subedi, Gauthami Viswan, Alpha T. N’Diaye, Rebecca Y. Lai, Peter A. Dowben
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2024-09-01 |
Deskripsi
The spin crossover complex Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> and its composite, Fe(phen)<sub>2</sub>(NCS)<sub>2</sub>, combined with the conducting polymer polyaniline (PANI) plus varying concentrations of iron magnetite (Fe<sub>3</sub>O<sub>4</sub>) nanoparticles were studied. A cooperative effect is evident from the hysteresis width in the plot of magnetic susceptibility multiplied by temperature versus temperature (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mi mathvariant="sans-serif">χ</mi></mrow><mrow><mi mathvariant="normal">m</mi></mrow></msub><mi mathvariant="normal">T</mi></mrow></semantics></math></inline-formula> versus T) for Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> with PANI plus varying concentrations of Fe<sub>3</sub>O<sub>4</sub> nanoparticles. The hysteresis width in the composites vary no more than 2 K with respect to the pristine Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> spin crossover crystallites despite the fact that there exists a high degree of miscibility of the Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> spin crossover complex with the PANI. The Fe<sub>3</sub>O<sub>4</sub> nanoparticles in the Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> plus PANI composite tend to agglomerate at higher concentrations regardless of the spin state of Fe(phen)<sub>2</sub>(NCS)<sub>2</sub>. Of note is that the Fe<sub>3</sub>O<sub>4</sub> nanoparticles are shown to be antiferromagnetically coupled with the Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> when Fe(phen)<sub>2</sub>(NCS)<sub>2</sub> is in the high spin state.