A valuable seminar was held in our department, presented by Dr. Diman Mohammad Abdullah , a lecturer in our Department. The seminar focused on the following topics:
The modified Debye–Callaway model was utilized to calculate the lattice thermal conductivity (LTC) in bulk, nanowires (NWs) Gallium Nitride (GaN) and GaN/AlN superlattice (SL). The longitudinal and transverse phonon modes were considered in the calculation. Various physical properties of GaN as a compound and alloy in NWs and SLs were determined, including Debye temperature, group velocity, melting enthalpy, melting entropy, vibrational entropy, lattice volume, mass density, surface roughness, Casimir length, dislocation concentration, scattering factor, and more. This work compared the lattice thermal conductivity to experimental data from the literature, covering a wide range of temperatures from very low to extremely high. Also, the modified Debye–Callaway model in combination with Murnaghan and Clapeyron equations was used to investigate the impact of hydrostatic pressure on LTC in bulk and NWs GaN. The last part of this work focused on the effect of grain boundary and alloy scattering on the temperature-dependent LTC of GaN/AlN SLs. The SL layers were considered as a grain, and the sample was treated as a multigrain.
