Thermal Conductivity of the Spin Peierls Compound CuGeO_3
  The thermal conductivity of the Spin-Peierls (SP) compound CuGeO_3 was measured in magnetic fields up to 16 T. Above the SP transition, the heat transport due to spin excitations causes a peak at around 22 K, while below the transition the spin excitations rapidly diminish and the heat transport is dominated by phonons; however, the main scattering process of the phonons is with spin excitations, which demonstrates itself in an unusual peak in the thermal conductivity at about 5.5 K. This low-temperature peak is strongly suppressed with magnetic fields in excess of 12.5 T. 
Yoichi Ando (1), J. Takeya (1), D.L. Sisson (2), S.G. Doettinger (2),   I. Tanaka (2,3), R.S. Feigelson (2), and A. Kapituln...