title: TEM characterization of As-deposited and annealed Ni/Al multilayer thin film.
abstract: Reactive multilayer thin films that undergo highly exothermic reactions are attractive choices for applications in ignition, propulsion, and joining systems. Ni/Al reactive multilayer thin films were deposited by dc magnetron sputtering with a period of 14 nm. The microstructure of the as-deposited and heat-treated Ni/Al multilayers was studied by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) in plan view and in cross section. The cross-section samples for TEM and STEM were prepared by focused ion beam lift-out technique. TEM analysis indicates that the as-deposited samples were composed of Ni and Al. High-resolution TEM images reveal the presence of NiAl in small localized regions. Microstructural characterization shows that heat treating at 450 and 700°C transforms the Ni/Al multilayered structure into equiaxed NiAl fine grains.
authors.affiliation: CEMUC, Department of Metallurgical and Materials Engineering, University of Porto, R. Dr. Roberto Frias, 4200-465 Porto, Portugal. sonia.simoes@fe.up.pt
authors.forename: S
authors.initials: S
authors.lastname: Simões
authors.forename: F
authors.initials: F
authors.lastname: Viana
authors.forename: A S
authors.initials: AS
authors.lastname: Ramos
authors.forename: M T
authors.initials: MT
authors.lastname: Vieira
authors.forename: M F
authors.initials: MF
authors.lastname: Vieira