Thermal Conductivity of Linear Chain Semiconductor (NbSe4)3I

We present measurements and analysis of the thermal conductivity, K(T), of the linear chain semiconductor (NbSe₄)₃I, which undergoes a phase transition beween two semiconducting phases at T_c=274K. The obtained data cover the range 100–340 K. The behaviour of K(T) is similar to that expected for insulating crystals, where K(T) is mainly governed by the umklapp processes. Beyond that, the thermal conductivity anomaly appears at T_c as a consequence of the structural phase transition that has been also seen in specific heat.