Enhanced Electron Heat Conduction in TaS3 1D Metal Wire

Abstract

The 1D wire TaS3 exhibits metallic behavior at room temperature but changes into a semiconductor below the Peierls transition temperature (T-p), near 210 K. Using the 3 omega method, we measured the thermal conductivity kappa of TaS3 as a function of temperature. Electrons dominate the heat conduction of a metal. The Wiedemann-Franz law states that the thermal conductivity kappa of a metal is proportional to the electrical conductivity sigma with a proportional coefficient of L-0, known as the Lorenz number-that is, kappa = sigma LoT. Our characterization of the thermal conductivity of metallic TaS3 reveals that, at a given temperature T, the thermal conductivity kappa is much higher than the value estimated in the Wiedemann-Franz (W-F) law. The thermal conductivity of metallic TaS3 was approximately 12 times larger than predicted by W-F law, implying L=12L(0). This result implies the possibility of an existing heat conduction path that the Sommerfeld theory cannot account for.