https://iopscience.iop.org/article/10.1088/2053-1591/ab68a0/pdf

Optical properties of transparent PMMA-PS/ZnO NPs polymeric nanocomposite films: UV-Shielding applications

We present the results of studies of the dielectric properties of nanocomposites based on Al2O3 oxide films with a pore size of 330 and 60 nm with particles of an organic ferroelectric diisopropylammonium bromide (C6H16BrN, DIPAB) introduced into the pores, aimed at determining the size dependences of phase transition parameters. A shift in the phase transition to low temperatures and diffusion of the transition are found, which become more significant for smaller pores. A broadening of the temperature hysteresis of the dielectric constant of nanocomposites during the phase transition was also observed. The decrease in the phase transition temperature in nanocomposites with DIPAB nanoparticles is consistent with theoretical models of the size effects on the structural phase transition.

Size Effect in Nanocomposites Based on Molecular Ferroelectric Diisopropylammonium Bromide

The study presents experimental results for investigating linear and nonlinear dielectric properties of nanocomposites based on bromide diisopropylammonium (C6H16NBr, DIPAB) and aluminum oxide films (Al2O3) with pore diameter of 330, 100 and 60 nm. It was indicated that the phase transition was blurred and shifted toward lower temperatures. This anomaly became more significant with decreasing pore size. The reduction of phase transition temperature in the nanocomposites, containing DIPAB, was consistent with theoretical models for the influence of size effects on the structural phase transition.

Dielectric properties of an organic ferroelectric of bromide diisopropylammonium embedded into the pores of nanosized Al 2 O 3 films.

This present work is devoted to clarifying the influence of hydrogen bonds on dielectric relaxation properties of classical hydrogen-bonded ferroelectrics (triglycine sulfate, Rochelle salt...

Effects of hydrogen bonds on dielectric relaxation of composites based on hydrogen-bonded ferroelectrics

We studied phase transitions in new organic ferroelectric DIPAI embedded into porous alumina and in bulk DIPAI. Complex permittivity and third harmonic generation coefficient were measured within a wide temperature range. The increase in the third harmonic generation indicates the emergence of the polar phase. Two phase transitions were seen in bulk DIPAI upon heating from room temperature after preliminary heating up to 420 K while only a transition was found upon cooling accompanied with pronounced thermal hysteresis. The ferroelectric phase was observed in the range between two transitions upon heating and below the transition upon cooling. In contrast, two phase transitions occur in DIPAI confined to porous alumina upon heating and cooling. The transitions do not show noticeable thermal hysteresis. It was suggested that different behavior of bulk and confined DIPAI results from slow kinetics of phase transitions in bulk upon cooling. The noticeable shift of the transition temperatures for DIPAI within alumina pores of different diameters was treated using the theories of size effects in ferroelectrics.

Phase transitions in bulk and confined organic ferroelectric DIPAI

The dielectric studies of diisopropylammonium chloride (DIPAC) nanoparticles embedded into opal and MCM-41 silica matrices are presented. It is shown that the ferroelectric phase transition shifts to low temperatures and broadens for DIPAC within the opal pores compared to bulk. The thermal hysteresis of the transition increases under opal nanoconfinement. No anomalies of the permittivity relevant to the ferroelectric transition are observed for DIPAC within the MCM-41 molecular sieves likely due to formation of the amorphous phase.

Impact of nanoconfinement on the diisopropylammonium chloride (C6H16ClN) organic ferroelectric

Temperature dependences of dielectric constant, amplitude of the third harmonic and heat capacity for the organic ferroelectric of diisopropylammonium iodide (C6H16NI) have been investigated. The m...

I. V. Egorova

Papers

Impact of nanoconfinement on the diisopropylammonium chloride (C6H16ClN) organic ferroelectric

Size Effect in Nanocomposites Based on Molecular Ferroelectric Diisopropylammonium Bromide

Dielectric properties of an organic ferroelectric of bromide diisopropylammonium embedded into the pores of nanosized Al 2 O 3 films.

Phase transitions in bulk and confined organic ferroelectric DIPAI

Dielectric properties of ferroelectric diisopropylammonium iodide