title: Structural and thermodynamic factors of suppressed interdiffusion kinetics in multi-component high-entropy materials.
abstract: We report multi-component high-entropy materials as extraordinarily robust diffusion barriers and clarify the highly suppressed interdiffusion kinetics in the multi-component materials from structural and thermodynamic perspectives. The failures of six alloy barriers with different numbers of elements, from unitary Ti to senary TiTaCrZrAlRu, against the interdiffusion of Cu and Si were characterized, and experimental results indicated that, with more elements incorporated, the failure temperature of the barriers increased from 550 to 900°C. The activation energy of Cu diffusion through the alloy barriers was determined to increase from 110 to 163 kJ/mole. Mechanistic analyses suggest that, structurally, severe lattice distortion strains and a high packing density caused by different atom sizes, and, thermodynamically, a strengthened cohesion provide a total increase of 55 kJ/mole in the activation energy of substitutional Cu diffusion, and are believed to be the dominant factors of suppressed interdiffusion kinetics through the multi-component barrier materials.
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Shou-Yi
authors.initials: SY
authors.lastname: Chang
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Chen-En
authors.initials: CE
authors.lastname: Li
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Yi-Chung
authors.initials: YC
authors.lastname: Huang
authors.affiliation: Department of Materials Science and Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Hsun-Feng
authors.initials: HF
authors.lastname: Hsu
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Jien-Wei
authors.initials: JW
authors.lastname: Yeh
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
authors.forename: Su-Jien
authors.initials: SJ
authors.lastname: Lin