Incorporated W Roles on Microstructure and Properties of W‐C:H Films by a Hybrid Linear Ion Beam Systems

Abstract

W-incorporated diamond-like carbon (W-C:H) films were fabricated by a hybrid beams system consisting of a DC magnetron sputtering and a linear ion source. The W concentration (1.08~31.74 at.%) in the film was controlled by varying the sputtering current. The cross-sectional topography, composition, and microstructure of the W-C:H films were investigated by SEM, XPS, TEM, and Raman spectroscopy. The mechanical and tribological properties of the films as a function of W concentration were evaluated by a stress-tester, nanoindentation, and ball-on-disk tribometer, respectively. The results showed that films mainly exhibited the feature of amorphous carbon when W concentration of the films was less than 4.38 at.%, where the incorporated W atoms would be bonded with C atoms and resulted in the formation ofWC1-xnanoparticles. The W-C:H film with 4.38 at.% W concentration showed a minimum value of residual compressive stress, a higher hardness, and better tribological properties. Beyond this W concentration range, both the residual stress and mechanical properties were deteriorated due to the growth of tungsten carbide nanoparticles in the carbon matrix.

Self‐Assembly of Rice Bran Globulin Fibrils in Electrostatic Screening: Nanostructure and Gels

“…Contrarily, at low ionic strength and pH, electrostatic repulsive force predominates the aggregates morphology and formed linear fibrils [7,11,12]. At low pH and low ionic strength, the gels have many advantages, for example, being transparent or semitransparent, being more elastic, and being of low gel critical concentration [13]. It may imply that the length of linear fibrils seems to be less than the wavelength of visible light, leading to the gels being transparent [14,15].…”