The hardness of aluminum films on silicon are measured as functions of depth of the indenter. The films have thicknesses of 0.25,0.5, and 1.0μm. The adhesion between one film and the substrate has been reduced through the prior deposition of a 10 nm layer of carbon. In each case the hardness is found to increase as the indenter approaches the film-substrate interface, but the rate of increase is greater for a film with good adhesion than for one with poor adhesion. It is suggested that this increase results from the constraint on deformation of the film by the substrate. A physical model is proposed whereby the yield stress of the film, σo, and an average effective shear strength τ of the indenter-film and film-substrate interfaces, may be determined from the data.
The saturation magnetization, 4πMs, and the magnetostriction constant, λ, of Ni81Fe19, Ni81Fe19/Ta and Ni72Fe17Rh11/ Ta thinfilms were studied as a function of film thickness before and after annealing. For films of thickness t < 200 Å, 4πMs, and λs were found to be strongly dependent on film thickness with even larger variation after annealing. Auger depth profiles have shown the existence of inhomogeneous interfacial layer at the film surface, Ta/film and film/substrate interfaces. The presence of such layers of different composition and magnetic properties from the film bulk, can explain the observed behavior of 4πMs and λs
Films of Fe50Mn50, 700 Å thick, were deposited on glass substrates by diode rf sputtering. Auger electron spectroscopy, and x-ray fluorescence analysis verified the film composition and x-ray diffraction determined the crystalline phase to be α-Mn(Fe), a complex bcc-like structure and a considerable deviation from that dictated by the equilibrium binary phase diagram. The films were annealed for 1 h at 260 °C and 10−7, 10−5, and 10−2 Torr. Auger depth profile analysis showed that (a) while no further oxidation (than that induced by ambient exposure) occurred during annealing at the lowest pressure, severe film oxidation took place at the highest pressure and (b) preferential surface oxidation of Mn resulted in a layered structure consisting of a surface Mn- and oxygen-rich layer followed by a region (deeper into the film) depleted in Mn and Fe enriched. The crystalline phases present were determined by x-ray diffraction analysis to be MnO (fcc) and α-Fe(Mn) (bcc). Magnetic measurements of the oxidized films revealed that they displayed in-plane isotropic ferromagnetic properties, with 4πMs∼15–18 kG for the most extensively oxidized films.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.