FEATURES IN ELECTRICAL CONDUCTIVITY OF COMPOSITE BASED ON MEDIUM-ENTROPY ALLOY BiSbTe1.5Se1.5 WITH AGGLOMERATED CARBON NANOTUBES FILLER
Year: 2025
Type: article
Abstract: The results of the electrical conductivity study for the composite samples consisting of medium-entropy BiSbTe1.5Se1.5 alloy (composite matrix) and multilayer carbon nanotubes (composite filler) with different filler contents, x, (0; 0.05; 0.1; 0.5; 1.0; 1.5 and 2.0 wt.%) at temperatures from 20 to 300 0C are presented in the paper. It was found that two types of inhomogeneities coexist in the bulk of the studied samples. The formation of microsized filler inclusions randomly distributed inside the matrix leads to microscale inhomogeneity. However, these inclusions themselves consist of agglomerated carbon nanotubes that corresponds to nanoscale inhomogeneity. As a result, composites with carbon nanotube fillers are highly inhomogeneous. With increasing temperature, the specific resistance of the sample, ρ, with x=0 (matrix alloy BiSbTe1.5Se1.5) monotonically increases up to a temperature of TINC≈520 K. Such behavior of ρ(T) corresponds to metals and degenerate semiconductors (metallic conductivity type). At room temperatures, the resistance ρ of the samples with x>0 increases with increasing filler content. With increasing temperature, the resistance of such samples begins to decrease, which corresponds to semiconductor behavior, i.e. introducing a filler from carbon nanotubes results in a change in the mechanism of electrical conductivity of the composite samples from metallic to semiconductor.
Source: COMPOSITES and NANOSTRUCTURES
Institution: Belgorod National Research University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7117297488