Magnetic field-dependent thermal transport in a spin-1/2 chain compound

We present experimental results on the thermal conductivity κ of the S = 1 / 2 chain compound copper pyrazine dinitrate ( C 4 H 4 N 2 ) ( NO 3 ) 2 at temperatures T between 0.37 and 10 K in magnetic fields B up to 17 T. The spin contribution κ s ( B , T ) parallel to the chains has been identified. At low temperatures, κ s ( B ) is characterized by two main features, namely a minimum at μ B B ∼ k B T and a plateau-like feature in the vicinity of the saturation field. Analysis of the high-field data suggests that the mean free path is surprisingly weakly dependent on both field and momentum.