Grain Size and Strain in Sputter Deposited Ni0.8Fe0.2 and Cu Films

The average grain size and strain in the direction parallel to the surface of thin Ni0.8Fe0.2 and Cu films, sandwiched between Ta layers, have been determined as a function of layer thickness by grazing incidence X-ray diffraction. The in-plane grain size and grain size distribution were also assessed by plan-view transmission electron microscopy. Standard ¿-2¿ X-ray powder diffraction was used to determine the uniform strain in the direction perpendicular to the surface. Both for Ni0.8Fe0.2 and Cu, an elongation of the lattice parameter perpendicular to the surface and a compression of the lattice parameter in the plane of the film is observed, which decreases with increasing film thickness. Additionally, for Ni0.8Fe0.2 a non-uniform elongation of the perpendicular interactomic distance at the Ta interfaces is deduced by fitting a kinematical model to the ¿-2¿ diffraction spectrum. This study illustrates the strength and the complementary character of standard powder X-ray diffraction, grazing incidence X-ray diffraction and transmission electron microscopy for the structural analysis of thin metal films

Grain Size and Strain in Sputter Deposited Ni0.8Fe0.2 and Cu Films

The average grain size and strain in the direction parallel to the surface of thin Ni0.8Fe0.2 and Cu films, sandwiched between Ta layers, have been determined as a function of layer thickness by grazing incidence X-ray diffraction. The in-plane grain size and grain size distribution were also assessed by plan-view transmission electron microscopy. Standard ¿-2¿ X-ray powder diffraction was used to determine the uniform strain in the direction perpendicular to the surface. Both for Ni0.8Fe0.2 and Cu, an elongation of the lattice parameter perpendicular to the surface and a compression of the lattice parameter in the plane of the film is observed, which decreases with increasing film thickness. Additionally, for Ni0.8Fe0.2 a non-uniform elongation of the perpendicular interactomic distance at the Ta interfaces is deduced by fitting a kinematical model to the ¿-2¿ diffraction spectrum. This study illustrates the strength and the complementary character of standard powder X-ray diffraction, grazing incidence X-ray diffraction and transmission electron microscopy for the structural analysis of thin metal films

Solid state magnetic resonance investigation of the thermally-induced structural evolution of silicon oxide-doped hydrogenated amorphous carbon

Due to their increased stability in extreme environments, relative to amorphous hydrogenated carbons (a-C:H), amorphous thin film silicon oxide-doped hydrogenated amorphous carbons (a-C:H:Si:O) are being commercially developed as solid lubricants and protective coatings. Although various properties of a-C:H:Si:O have been investigated, no definitive structure of a-C:H:Si:O has ever been proposed, nor has its thermally-induced structural evolution been thoroughly studied. The aim of this work is to better understand the structure of a-C:H:Si:O through solid-state nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopies. Deeper insights into the thermally-driven structural evolution are obtained by annealing a-C:H:Si:O between 50 °C and 300 °C under anaerobic conditions and taking NMR/EPR measurements after each step. EPR results show that the number of paramagnetic defects decreases by 70% with annealing at 300 °C. ¹H NMR shows the hydrogen concentration decreases with annealing temperature from 2 × 10²² g−¹, and then levels off at approximately 0.7 × 10²² g−¹ for anneals between 200 °C and 300 °C. The carbon–silicon–oxygen network exhibits some structural reorganization, seen directly as a slight increase in the sp²/sp³ ratio in the ¹³C NMR with annealing. These results combined with relaxation data are interpreted according to a two-component structure largely defined by differences in hydrogen and defect contents

Abrasion resistant low friction diamond-like multilayers

Over the past few years, we have investigated plasma deposited amorphous hydrogenated carbon (DLC) films modified with B, N and Si dopants. Whereas, all three elements have the advantage to induce stress relief in the films (combined with hardness reduction), Si appeared to be the most interesting alloying element for tribological applications (friction and wear). Following this work, multilayer coatings consisting of a stack of DLC layers alternated with Si-doped DLC films and more recently, diamond-like nanocomposite (Dylyn (R), a-C:H/a-Si:O) films were developed. A major advantage of the multilayer structure is the stress relief enabling the deposition of thick layers (10 mum) without any loss of good adhesion properties. These thick multilayers show improved abrasion resistance as well as extremely low friction properties (friction coefficient <0.1 independent of the relative humidity). This paper discusses the mechanical and tribological properties of these multilayer coatings and presents a comparison to various other layer systems (TiN, CrN and hard Cr). (C) 2001 Elsevier Science B.V. All rights reserved.status: publishe