Thermal expansion coefficient of ScN(111) thin films grown on Si(111) determined by X-ray diffraction

Scandium nitride (ScN) has emerged as a promising material in various fields due to its exceptional characteristics, including high mechanical strength, hardness, high melting point, high thermal stability, and wide bandgap. This work investigates the thermal behavior of ScN by the measurement of its coefficient of linear thermal expansion (TEC). A (111)-oriented ScN thin film on a (111)-oriented Si substrate is used for the measurements. The lattice parameter is determined using x-ray diffraction, and in situ measurements are performed at elevated temperatures of up to 923 K. The expansion of the material with increasing temperature is modeled using Debye's phonon dispersion. The fitted lattice parameters are used to calculate the TEC, which we measured to be (6.61±0.60)×10−6 K−1 at 300 K. Thus, the value is 1.37×10−6 K−1 lower than the value published by Tahri et al. [J. Phys.: Condens. Matter 24, 035401 (2011)]. who simulated the TEC for a ScN bulk crystal. This work contributes to the knowledge on thermal properties of ScN and paves the way for further research in this field.