Anomalous Phase Transition, Polarization Switching, and Relaxation in a Novel Composite Consisting of Dimethylammonium Aluminum Sulfate Hexahydrate and Oxidized Multiwalled Carbon Nanotubes

Abstract

A novel ferroelectric composite consisting of dimethylammonium aluminum sulfate hexahydrate (CH₃)₂NH₂Al(SO₄)₂·6H₂O and oxidized multiwalled carbon nanotubes was developed to investigate its dielectric relaxation, phase transition, and ferroelectric switching behaviors. Experimental methods combined with theoretical analyses were employed. The results showed that the filler of oxidized multiwalled carbon nanotubes caused the freezing of domain-wall motion in (CH₃)₂NH₂Al(SO₄)₂·6H₂O at 98.2 K, leading to a decrease in dielectric constant, dielectric loss, and the polarization. In addition, an increase in dielectric permittivity and dielectric loss was found at higher temperatures. The role of hydroxyl groups incorporated in the carbon nanotubes after its oxidation was responsible for the obtained anomalies.

Keywords:

• dielectric relaxation
• dimethylammonium aluminum sulfate hexahydrate
• ferroelectric composite
• ferroelectricity
• oxidized multiwalled carbon nanotubes

Disclosure statement

The author declares no competing interests.

Additional information

Funding

No funding was received to assist with the preparation of this manuscript.