Anisotropic heat conduction in the metal organic framework perovskites [C(NH_2)_3]X(HCOO)_3 (X = Cu, Zn)

摘要

We report thermal conductivity (kappa) measurements on single crystals of the metal-organic framework perovskite compounds [C(NH2)(3)]X(HCOO)(3) (X = Cu, Zn) in the temperature range 5 K = T = 300 K. The directionality of N-H...O bonds and their stretching due to the Jahn-Teller distortion in the Cu compound are identified as mechanisms underlying differences in the kappa(T) behavior for the two compounds and their anisotropy. For heat flow along a direction preferentially transverse to the N-H...O bonds, kappa similar to 0.6W/mK near 300 K, approaching the theoretical minimum value. A possible magnetic contribution to the heat flow in the Cu compound is also discussed. Published under license by AIP Publishing.