A polyfluoroalkylmethacrylate (PFAM) film has been coated on the surface of the magnetic head by a dipping coating method to modify the surface properties. The films were characterized by means of a time-of-flight secon- dary ion mass spectrometer (TOF-SIMS), contact angle measurement and atomic force microscopy (AFM). The re- sults indicate that the concentration of the solution is the main factor affecting the thickness, contact angle and surface topography of the film. The magnetic head with the PFAM film at a concentration of 500 ppm exhibits the best tribology properties, and the stiction between the magnetic head and the disk is no more than 2.4 g after 20000 contact start stop (CSS) cycles. Therefore, a fully covered PFAM film with few defects helps improve the tribology properties of the mag- netic head, and decrease the adsorbed contaminant on the magnetic head surface.
利用高分辨透射电子显微镜和原子力显微镜观察了含纳米颗粒溶液冲蚀硅片表面损伤行为,考察了纳米颗粒碰撞单晶硅片所导致的微观物理损伤.结果表明:冲蚀30 s后,在高分辨透射电子显微镜下可见硅片表面呈现方向性损伤,并可观察到大量非均匀的晶格缺陷;当冲蚀10 m in时,硅片表面出现微观划痕和凹坑,在划痕一端可见原子堆积,亚表面可观察到镶嵌晶粒的非晶损伤层;继续延长冲蚀时间将加剧其表面损伤.
This paper reports that amorphous silicon nitride （a-SiNx） overcoats were deposited at room temperature by microwave ECR plasma enhanced unbalanced magnetron sputtering. The 2 nm a-SiNs overcoat has better anti-corrosion properties than that of reference a-CNx overcoats （2 4.5 nm）. The superior anti-corrosion performance is attributed to its stoichiometric bond structure, where 94.8% Si atoms form Si-N asymmetric stretching vibration bonds. The N/Si ratio is 1.33 as in the stoichiometry of Si3N4 and corresponds to the highest hardness of 25.0 GPa. The surface is atomically smooth with RMS 〈 0.2 nm. The ultra-thin a-SiNx overcoats are promising for hard disks and read/write heads protective coatings.
Carbon nitride films were deposited by a twinned microwave electron cyclotron resonance （ECR） plasma source enhanced unbalanced magnetron sputtering system. The results indicate that the structure of the films is sensitive to the nitrogen content. The increase in the nitrogen flow ratio leads to an increase in the sp3 content and an improvement of the tribological properties.
The wearless friction originating from molecular interactions has been discussed in this paper. We find that the frictional properties are closely related to the structural match of two surfaces in relative motion. For the surfaces with incommensurate structure and week inter-surface interaction, zero static and kinetic friction can be achieved. In a sliding considered as in a quasi-static state, the energy dissipation initiates when interfacial particles move in a discontinuous fashion, which gives rise to a finite kinetic friction. The state of superlubricity is a result of computer simulations, but the prediction will encourage people to look for a technical approach to realizing the state of super low friction.
To overcome the complicated and time-consuming difficulties of current models, a new lubrication equation based on boundary velocity slip model for solving the ultra-thin film gas lubrication in hard disk drives is proposed by adopting the nanoscale effect function, Np. The present model is easy to calculate and applicable at nanoscale.The results of numerical calculations indicate that the present model produces a close approximation to that of the exact Boltzmann model.
