  High-entropy alloys (HEAs) are attracting attention due to their exceptional
properties, such as enhanced mechanical toughness, superconducting robustness,
and thermoelectric performance. Numerous HEAs have been developed for diverse
applications, ranging from self-healing in fusion reactors to addressing
environmental concerns with thermoelectric materials. Understanding atomic
diffusion within HEA crystals is crucial for these applications. Here, this
study investigates diffusion mechanisms in PbTe-based HEAs, focusing on the
role of indium (In). Molecular dynamics simulations reveal that In inclusion
prompts spontaneous Frenkel defect formation, notably enhancing diffusion not
only of In$^+$ but also other cations. Frenkel defect formation, closely linked
to alloy properties, is predominantly influenced by charge rather than cation
size. This insight not only enhances comprehension of HEA diffusion mechanisms
but also develops HEAs with properties such as self-healing from damage and
high ion permeability, advancing the field of material science.
