Shannon Entropy Characterization of High-Entropy Thin Films Synthesized by Pulsed Magnetron Sputtering: The Influence of Modulation Frequency

Abstract This manuscript presents a comprehensive study of the synthesis of high-entropy TiCrFeCoNi alloy (HEA) thin films via pulsed magnetron sputtering (PMS).The research investigates the impact of various modulation frequencies on the material properties of the synthesized films. By employing Shannon entropy as a novel method to characterize the complexity and homogeneity of high-entropy thin films, we offer new insights into the synthesis process under various thermodynamic conditions. The initial characterization of the alloy, using calculated parameters such as mixing entropy, enthalpy of mixing, and others, sets the stage for a deeper understanding of the alloy's formation and stability. The experimental methodology encompasses target synthesis, sputtering system setup, sample synthesis, and comprehensive process and sample characterization, including EDS analysis, surface and cross-sectional analyses using SEM, and mechanical property assessments via nanoindentation. Results indicate that modulation frequency significantly influences the plasma discharge process, and consequently, the composition, microstructure, and mechanical properties of the HEA films. EDS analysis confirms the successful synthesis of the target alloy composition, and surface and cross-sectional analyses reveal the effects of modulation frequency on film morphology and structure. Mechanical property measurements highlight the variations in hardness and Young’s modulus among the synthesized films. The study elucidates the role of PMS parameters, especially modulation frequency, in controlling the synthesis of high-entropy thin films, paving the way for optimizing film properties for advanced material applications. Graphical Abstract