The thermal conductivity of CsMnCl3 . 2H2O (CMC) - a quasione- dimensional antiferromagnet with spin 5/2 has been studied in the temperature range from 2 to 25K in zero magnetic field. The analysis of the data performed within Debye model revealed the combined effect of the single-ion and volume magnetostriction in the vicinity of a phase transition.
Thermal-conductivity calculations based on the model and corresponding experimental studies showed that the poor sample quality and small dimensions can suppress the manifestation of a spin-phonon coupling present in CMC.