Fabrication of PtIrPd Noble Metal Medium Entropy Alloy Thin Film by Atomic Layer Deposition. Issue 3 (17th November 2022)

• Record Type: Journal Article
• Authors: Zou, Yiming; Jing, Lin; Wang, Leyan; Tan, Hui Teng; Goei, Ronn; Yong, Sidney Kwong Roong; Ong, Amanda Jiamin; Tan, Kwan W.; Tok, Alfred Iing Yoong
• Is Part Of: Advanced engineering materials. Volume 25:Issue 3(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-17
• Subjects: atomic layer deposition -- electric Joule heating -- medium entropy alloys -- noble metals -- thin films; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.202201263
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Noble metal medium entropy alloy (MEA) thin films have recently attracted enormous research interests recently because of their great potential in the catalytic application. However, conventional bottom‐up fabrication methods for MEA thin film such as magnetron sputtering face enormous challenges including precise control over film thickness and consumption of costly high‐purity noble metal targets. Herein, a facile and tunable approach is developed coupling sequential atomic layer deposition (ALD) of noble metal layers with electric Joule heating (EJH) alloying process to grow platinum‐iridium‐palladium (PtIrPd) MEA thin films. The PtIrPd MEA thin film with a thickness of ≈20 nm and an atomic ratio of 35:35:30 is successfully fabricated. The effect of EJH processing temperature on the film morphology and structure evolution is investigated. ALD provides flexibility in the metal deposition sequence with meticulous thickness control and atomic composition precision, while the ultrafast EJH ramping/cooling rates promote homogeneous alloying of MEA combinations inhibiting phase separation. Furthermore, the integrated method circumvents a major obstacle of finding a common ALD temperature window for different noble metal precursors as well as opens new pathways for the controllable synthesis of multicomponent metal alloy thin films with potential catalytic, magnetic, and optical properties. Abstract : Noble metal‐based (Pt, Ir, Pd) medium‐entropy alloy (MEA) thin film is fabricated by sequential atomic layer deposition (ALD), followed by electric Joule heating. This novel two‐step method gives precise control over thickness and tunable atomic ratio of the MEA thin film. The PtIrPd MEA thin film with thickness of ≈20 nm is successfully fabricated.