关键词: dirac semimetals, Cd₃As₂, thermal conductivity, phonon scattering

Abstract: Lattice thermal conductivity (LTC) of cadmium arsenide (Cd$_{3}$As$_{2}$) is studied over a wide temperature range (1-400 K) by employing the Callaway model. The acoustic phonons are considered to be the major carriers of heat and to be scattered by the sample boundaries, disorder, impurities, and other phonons via both Umklapp and normal phonon processes. Numerical calculations of LTC of Cd$_{3}$As$_{2}$ bring out the relative importance of the scattering mechanisms. Our systematic analysis of recent experimental data on thermal conductivity (TC) of Cd$_{3}$As$_{2}$ samples of different groups, presented in terms of LTC, $\kappa_{\scriptscriptstyle{\rm L}}$, using a nonlinear regression method, reveals good fits to the TC data of the samples considered for $T< \sim 50 $ K, and suggests a value of 0.2 for the Gruneisen parameter. It is, however, found that for $T> 100 $ K the inclusion of the electronic component of TC, $\kappa_{\rm e}$, incorporating contributions from relevant electron scattering mechanisms, is needed to obtain good agreement with the TC data over the wide temperature range. More detailed investigations of TC of Cd$_{3}$As$_{2}$ are required to better understand its suitability in thermoelectric and thermal management devices.

Key words: dirac semimetals, Cd₃As₂, thermal conductivity, phonon scattering