Scanning probe microscopy and microwave phenomena in composite containing iron nanoparticles and carbon nanotubes

Abstract

Epoxyamine matrix-based composites containing 15 wt% of Fe nanoparticles and 1.5 or 2 wt% of carbon nanotubes, as well as composites containing only Fe particles, have been studied using microwave methods and various scanning probe microscopy techniques, such as scanning capacitance microscopy and scanning Kelvin probe force microscopy. The composites were prepared using technological methods that improve their homogeneity. Probe current dependences investigated by applying different voltages to the probe in the Kelvin probe force microscopy mode have shown that the falling regions of the dependences at both positive and negative values of the bias voltage are found only for the sample containing both the Fe particles and the CNT in the “soft epoxy” matrix. Microwave measurements of the transmission and reflection coefficients were performed in the frequency range from 26 to 38 GHz. The field dependences of the microwave power dissipation have been plotted. The ferromagnetic resonance in the composites has been investigated. Frequency dependences of the complex dielectric permittivity of the composites have been determined. Microwave properties of the CNT-containing and CNT-free composites have been compared.

Keywords:

• Carbon nanotubes
• Fe particles
• magnetic composites
• scanning probe microscopy
• fractal dimension
• microwave properties
• ferromagnetic resonance

Acknowledgments

Electron microscopy examinations using Quanta-200 scanning microscope and SPM studies were carried out at the Collaborative Access Center “Testing Center of Nanotechnology and Advanced Materials” of IMP UB RAS.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The results were obtained within the state assignment of the Ministry of Science and Education of Russia (theme “Magnet” No 122021000034-9 and theme “Spin” No 122021000036-3).