Stability and Thermodynamic Properties of High-Entropy TiNbZrHfTa Alloy Films

High-entropy alloys represent a new class of materials characterized by high configuration entropy and unique properties, such as strength and ductility at various temperatures. This paper considers the TiNbZrHfTa alloy, which was synthesized as thin films using vacuum arc plasma-assisted deposition. The study was performed using X-ray diffraction analysis, the inverse convex hull method, and first-principles calculations within the quasi-harmonic approximation. It has been established that the TiNbZrHfTa alloy is qualified as a stable structure near the melting point. The temperature range of structural stability was found to be T = 1578–2935 K. It is shown that the alloy lattice belongs to the class of single-phase X-ray amorphous structures. A crystallographic database of orthogonal alloy lattices has been created. It has been found that the structural state of the amorphous alloy is determined by a simple cubic lattice, for which crystallographic information is provided.