In situ N K‐edge XANES study of iron, cobalt and nickel nitride thin films. (10th August 2021)

• Record Type: Journal Article
• Authors: Pandey, Nidhi; Gupta, Mukul; Phase, D. M.; Gupta, Ajay
• Is Part Of: Journal of synchrotron radiation. Volume 28:Part 5(2021)
• Page Start: 1504
• Page End: 1510
• Publication Date: 2021-08-10
• Subjects: soft X‐ray absorption spectroscopy -- in situ studies -- N K‐edge XANES -- transition metal nitrides -- reactive sputtering -- X‐ray absorption spectroscopy -- 3d transition metal nitride thin films; Synchrotron radiation -- Periodicals; Free electron lasers -- Periodicals; 539.73505
• DOI: 10.1107/S1600577521006822
• Languages: English
• ISSNs: 0909-0495

Abstract

Abstract : Sputter deposition is combined with in situ N K ‐edge absorption measurements to study thin films of magnetic nitrides (Fe‐N, Co‐N, Ni‐N) ranging from sub‐monolayer to bulk. Ultra‐thin films of these nitrides were found to demonstrate a different behavior that can be coupled with structural changes taking place with the increasing film thickness. Abstract : A prototype in situ X‐ray absorption near‐edge structure (XANES) system was developed to explore its sensitivity for ultra‐thin films of iron‐nitride (Fe‐N), cobalt‐nitride (Co‐N) and nickel‐nitride (Ni‐N). They were grown using DC‐magnetron sputtering in the presence of an N2 plasma atmosphere at the experimental station of the soft XAS beamline BL01 (Indus‐2, RRCAT, India). XANES measurements were performed at the N K ‐edge in all three cases. It was found that the N K ‐edge spectral shape and intensity are greatly affected by increasing thickness and appear to be highly sensitive, especially in low‐thickness regions. From a certain thickness of ∼1000 Å, however, samples exhibit a bulk‐like behavior. On the basis of the obtained results, different growth stages were identified. Furthermore, the presence of a molecular N2 component in the ultra‐thin regime (<100 Å) was also obtained in all three cases studied in this work. In essence, this prototype in situ system reveals that N K ‐edge XANES is a powerful technique for studying ultra‐thin films, and the development of a dedicated in situ system can be effective in probing several phenomena that remain hitherto unexplored in such types of transition metal nitride thin films.