Low thermal conductivity of the negative thermal expansion material, HfMo2O8
Kennedy, Catherine A.
White, Mary Anne
Wilkinson, Angus P.
MetadataShow full item record
The thermal conductivity of the cubic polymorph of hafnium molybdate, HfMo2O8, was determined over the temperature range of 2-400 K. The values of thermal conductivity were low (0.64 +/- 0.15 W m(-1) K-1 at T=300 K for a fully dense sample), with a positive temperature coefficient throughout the temperature range examined. Calculations of the theoretical minimum thermal conductivity and the effective phonon mean free path show that the heat-carrying phonons are nearly fully coupled in HfMo2O8, consistent with the rather large magnitude of its Gruneisen parameter. The low-frequency optic modes which lead to negative thermal expansion in HfMo2O8 are likely responsible for the low thermal conductivity. (c) 2007 American Institute of Physics.
Kennedy, Catherine A., Mary Anne White, Angus P. Wilkinson, and Tamas Varga. 2007. "Low thermal conductivity of the negative thermal expansion material, HfMo2O8." Applied Physics Letters 90(15): 151906-151906.