NOMATEN HYBRID-SEMINAR June 18: From Plasma to Properties: Designing High-Entropy Thin Films

High-entropy materials are often presented as a new paradigm in materials science, where configurational disorder is expected to stabilise novel phases and unlock exceptional properties. However, as research progresses, it becomes increasingly clear that entropy is only one part of a much more complex picture.

In this seminar, we will explore high-entropy thin films as model systems for studying materials far from equilibrium. Using magnetron sputtering - and in particular High Power Impulse Magnetron Sputtering (HiPIMS) - we demonstrate how plasma conditions can be used to deliberately tailor microstructure, defect populations, and phase formation pathways. These approaches allow access to metastable states that cannot be achieved in bulk materials, effectively turning thin films into a laboratory for non-equilibrium thermodynamics.

We will discuss refractory high-entropy nitrides as model systems, where the interplay between chemistry, vacancies, and ion-driven growth governs mechanical performance and thermal stability. These insights will then be extended towards high-entropy oxides for lithium- and sodium-ion batteries, where disorder and defect chemistry can critically influence ion storage and transport.

Rather than viewing entropy as a universal stabilising factor, this work argues for a more general design strategy based on the full thermodynamic landscape, including defect energetics and growth pathways. Such an approach opens new opportunities for designing materials with tailored functionalities across both structural and energy applications.