Determination of in-plane thermal conductivity of Nax Co2O4 single crystals via a parallel thermal conductance (PTC) technique

• Published in: Physica status solidi. A, Applications and materials science Vol. 205; no. 5; pp. 1152 - 1156
• Main Authors: Tang, Xiaofeng, Aaron, Kelvin, He, Jian, Tritt, Terry M.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2008; WILEY‐VCH Verlag
• Subjects: 63.20.−e; 66.70.Lm; 72.15.Jf; 81.05.Je
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.200824028

A novel parallel thermal conductance (“PTC”) system was specifically developed to conduct the steady state thermal conductivity measurement on small size samples such as single crystals of Nax Co2O4 as reported here. The accuracy and reproducibility of the PTC system has been confirmed by measuring several standard reference materials. The in‐plane thermal conductivity κ of Nax Co2O4 single crystals grown by a NaCl flux method was measured from 10 K to 300 K and κ was found to be ∼5 W m–1 K–1 at 300 K. The phonon mean free path (MFP) is estimated to be lph ∼ 9 Å at 300 K, which is comparable to the lattice constant but much smaller than the reported MFP of conducting carriers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)