Heat transport of the quasi-one-dimensional Ising-like antiferromagnet BaCo2V2O8 in longitudinal and transverse fields.

The very-low-temperature thermal conductivity (κ) is studied for BaCo2V2O8, a quasi-one-dimensional Ising-like antiferromagnet exhibiting an unusual magnetic-field-induced order-to-disorder transition. The nearly isotropic transport in the longitudinal field indicates that the magnetic excitations scatter phonons rather than conduct heat. The field dependence of K shows a sudden drop at ∼4 T, where the system undergoes the transition from the Néel order to the incommensurate state. Another dip at lower field of ∼3 T indicates an unknown magnetic transition, which is likely due to the spin-flop transition. Moreover, the K{H) in the transverse field shows a very deep valleylike feature, which moves slightly to higher field and becomes sharper upon lowering the temperature. This indicates a magnetic transition induced by the transverse field, which however is not predicted by the present theories for this low-dimensional spin system. [ABSTRACT FROM AUTHOR]