The Effects of Pressure and Size Parameter on the Lattice Thermal Conductivity in Multilayer Hexagonal Boron Nitride

The shift in lattice thermal conductivity of multilayer hexagonal boron nitride is studied as a function of layer thickness, hydrostatic pressure, and temperature. A Morelli–Callaway model is used for pressures ranging from zero to 7 GPa and temperatures scale from 2 to 350 K. Hydrostatic pressure and size parameters such as the mean bond length, melting temperature, and bulk modulus affect the lattice thermal conductivity of bulk and multilayer hexagonal Boron Nitride. The peak value of lattice thermal conductivity for both bulk and multilayer is seen to fall when pressure is increased, and the decline in lattice thermal conductivity is greater as the number of layers decreases. The drop in thermal conductivity is due to a reduction in phonon movement in the system as the number of layers decreases. The Morelli–Callaway model based on Clapeyron–Murnaghan equations is an effective approach for determining the pressure impact of lattice thermal conductivity. The lattice thermal conductivity declined as pressure is reduced, and the mass density and bulk modulus decreased as the thickness of the thin layer increased, while compressibility, solid molar volume, and liquid molar volume rose. When the experimental data and theoretical calculations for bulk and multilayer h-BN were compared, the findings indicated good agreement. It's crucial to lower the heat conductivity of the materials that are useful for device applications.