Thermal conductivity measurements of single-crystalline bismuth nanowires by the four-point-probe 3-ω technique at low temperatures

• Published in: Nanotechnology Vol. 24; no. 18; p. 185401
• Main Authors: Lee, Seung-Yong, Kim, Gil-Sung, Lee, Mi-Ri, Lim, Hyuneui, Kim, Wan-Doo, Lee, Sang-Kwon
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 10.05.2013; Institute of Physics
• Subjects: Bismuth; Compressive properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Heat transfer; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanoscale materials and structures: fabrication and characterization; Nanowires; Other topics in nanoscale materials and structures; Physical properties of thin films, nonelectronic; Physics; Quantum wires; Scattering; Single crystals; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Theory and models of film growth; Thermal conductivity; Thermal stability; thermal effects; Transport; Temperature dependence; Phonons; Chip; Ion beams; Thermoelectric materials; Compressive stress; Monocrystals; Electrical conductivity measurement; Growth mechanism; Bismuth; Thermal conductivity; Nanowires; Phonon scattering; Nanostructured materials; Thermal stresses
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/24/18/185401

We have successfully investigated the thermal conductivity (κ) of single-crystalline bismuth nanowires (BiNWs) with [110] growth direction, via a straightforward and powerful four-point-probe 3-ω technique in the temperature range 10-280 K. The BiNWs, which are well known as the most effective material for thermoelectric (TE) device applications, were synthesized by compressive thermal stress on a SiO2/Si substrate at 250-270 °C for 10 h. To understand the thermal transport mechanism of BiNWs, we present three kinds of experimental technique as follows, (i) a manipulation of a single BiNW by an Omni-probe in a focused ion beam (FIB), (ii) a suspended bridge structure integrating a four-point-probe chip by micro-fabrication to minimize the thermal loss to the substrate, and (iii) a simple 3-ω technique system setup. We found that the thermal transport of BiNWs is highly affected by boundary scattering of both phonons and electrons as the dominant heat carriers. The thermal conductivity of a single BiNW (d ∼ 123 nm) was estimated to be ∼2.9 W m−1 K−1 at 280 K, implying lower values compared to the thermal conductivity of the bulk (∼11 W m−1 K−1 at 280 K). It was noted that this reduction in the thermal conductivity of the BiNWs could be due to strongly enhanced phonon-boundary scattering at the surface of the BiNWs. Furthermore, we present temperature-dependent (10-280 K) thermal conductivity of the BiNWs using the 3-ω technique.