| Title |
Low frequency noise characteristics of composites with carbon nanoparticles |
| Translation of Title |
Kompozitų su anglies nanodalelėmis žemo dažnio triukšmo charakteristikos. |
| Authors |
Venkata Sai Mohan Revanth, Vakada |
| Full Text |
|
| Pages |
41 |
| Keywords [eng] |
composite, carbon nanotubes, carbonized copper, low frequency noise, charge transfer mechanisms. |
| Abstract [eng] |
The aim of this work is to investigate the resistive and low-frequency noise characteristics of epoxy resin matrix composites with multi-walled carbon nanotubes (CNT) and carbon-coated copper nanoparticles (Cu@C) fillers.Resistivity and low-frequency noise (10 Hz – 20 kHz) studies were performed at room temperature, in the voltage range from 4.5 V to 55 V, and by changing the temperature of the composite sample in the range from 75 K to 365 K at a constant voltage of 9.12 V. Single-phase Cu@C and multi-phase CNT/Cu@C composites with different filler concentrations were studied.The resistivity of the composites depends on the type and concentration of fillers. Composites with higher filler concentrations have lower resistivity. Multi-phase CNT/Cu@C composites have lower resistivity than single-phase Cu@C composites at comparatively lower filler concentrations due to the higher CNT aspect ratio. Also, the resistivity of single-phase Cu@C composites is more dependent on the thermal expansion of the matrix.Charge transfer in the studied composites is a thermally activated process. The Arrhenius thermal activation model is applicable to the temperature dependence of the resistivity of the composites with Cu@C fillers in the range from 75 K to 145 K. The fluctuation-induced tunneling model is applicable to the temperature dependence of the resistivity of composites with CNT and Cu@C fillers in the range from 75 K to 193 K.In the investigated frequency range from 10 Hz – 20 kHz, the low-frequency noise of the composites is of the 1/f type. The noise level of the single-phase composites with 10 or 15 vol.% Cu@C is proportional to the square of the voltage, which is characteristic of noise arising from impedance fluctuations.The noise level of the remaining composites is proportional to the voltage, which is associated with a more significant contribution of tunneling phenomena. |
| Dissertation Institution |
Vilniaus universitetas. |
| Type |
Master thesis |
| Language |
English |
| Publication date |
2026 |
