Phonon–spin scattering and magnetic heat transport in the quasi-one-dimensional spin−12 antiferromagnetic chain compound CuSb2O6

We report measurements of thermal conductivity (κ) on single crystals of the quasi-one-dimensional spin−1/2 anitferromagnetic chain compound CuSb2O6 and its nonmagnetic analog ZnSb2O6 in the temperature range 5K≤T≤300K. A substantially lower κ for CuSb2O6 compared to that of ZnSb2O6 has its origin in resonant phonon–spin scattering involving excitation of a two-level system (energyscale∼100K) associated with the onset of local spin order at T≤150K. Anisotropy in κ for the CuSb2O6 also emerges at T≤150 K and might be associated with a magnetic contribution to heat transport. A magnetic mean free path comparable to that of other spin−1/2 linear-chain compounds (∼0.3μm) is implied.