Formation Mechanism of Laser‐Synthesized Iron–Manganese Alloy Nanoparticles, Manganese Oxide Nanosheets and Nanofibers. (9th January 2017)

• Record Type: Journal Article
• Authors: Zhang, Dongshi; Ma, Zheng; Spasova, Marina; Yelsukova, Anna E.; Lu, Suwei; Farle, Michael; Wiedwald, Ulf; Gökce, Bilal
• Is Part Of: Particle and particle systems characterization. Volume 34:Number 3(2017:Mar.)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-01-09
• Subjects: laser ablation in liquids -- manganese iron alloys -- manganese oxides -- nanofibers -- nanosheets -- particle attachment mechanisms -- phase changes; Particles -- Periodicals; 620.43
• DOI: 10.1002/ppsc.201600225
• Languages: English
• ISSNs: 0934-0866

Abstract

Abstract : Laser ablation in liquids (LAL) has emerged as a versatile approach for the synthesis of alloy particles and oxide nanomaterials. However, complex chemical reactions often take place during synthesis due to inevitable atomization and ionization of the target materials and decomposition/hydrolysis of solvent/solution molecules, making it difficult to understand the particle formation mechanisms. In this paper, a possible route for the formation of FeMn alloy nanoparticles as well as MnO x nanoparticles, ‐sheets, and ‐fibers by LAL is presented. The observed structural, compositional, and morphological variations are clarified by transmission electron microscopy (TEM). The studies suggest that a reaction between Mn atoms and Fe ions followed by surface oxidation result in nonstoichiometric synthesis of Fe‐rich FeMn@FeMn2 O4 core–shell alloy particles. Interestingly, a phase transformation from Mn3 O4 to Mn2 O3 and finally to Ramsdellite γ‐MnO2 is accompanied by a morphology change from nanosheets to nanofibers in gradually increasing oxidizing environments. High‐resolution TEM images reveal that the particle‐attachment mechanism dominates the growth of different manganese oxides. Abstract : The formation mechanism of FeMn nanoalloys and MnO x nanoparticles, ‐sheets, and ‐fibers synthesized by laser ablation in different liquids is elucidated. In particular, a phase transformation from Mn3 O4 to Mn2 O3 and finally to Ramsdellite γ‐MnO2 in gradually increasing oxidizing environments is revealed, unveiling how manganese oxides evolve under different ambient conditions.