Lattice thermal conductivity modelling of a diatomic nanoscale material

Introduction: A new approach for expressing the lattice thermal conductivity of di-atomic nanoscale materials is developed. Methods: The lattice thermal conductivity of two samples of GaAs nanobeam at 4-100K is calcu-lated on the basis of monatomic dispersion relation. Phonons are scattered by nanobeam bounda-ries, point defects and other phonons via normal and Umklapp processes. Results: A comparative study of the results of the present analysis and those obtained using Callaway formula is performed. We clearly demonstrate the importance of the utilised scattering mechanisms in lattice thermal conductivity by addressing the separate role of the phonon scattering relaxation rate. The formulas derived from the correction term are also presented, and their dif-ference from Callaway model is evident. Furthermore their percentage contribution is sufficiently small to be neglected in calculating lattice thermal conductivity. Conclusion: Our model is successfully used to correlate the predicted lattice thermal conductivity with that of the experimental observation. © 2020 Bentham Science Publishers.