Tribochemical Effects of Various Gases and Water Vapor on Thin Film Magnetic Disks With Carbon Overcoats

1991 ◽  
Vol 113 (4) ◽  
pp. 689-693 ◽  
Author(s):  
B. D. Strom ◽  
D. B. Bogy ◽  
C. S. Bhatia ◽  
B. Bhushan
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
Carbon Film ◽  
Adsorbed Water ◽  
Friction Behavior ◽  
Gaseous Oxygen ◽  
Magnetic Disks ◽  
Write Heads ◽  
Carbon Overcoats

Friction tests on thin film magnetic disks with carbon overcoats were performed using commercial read/write heads as sliders. The results provide evidence that the thin film overcoats wear through chemical means in the presence of gaseous oxygen, and through mechanical means in the absence of oxygen. When small concentrations of water are present, friction behavior resembling that of an oxidizing environment is observed, suggesting oxidation of the carbon film preceded by dissociation of adsorbed water.

Friction and Wear Micromechanisms of Amorphous Carbon Thin Films

1997 ◽  
Vol 119 (4) ◽  
pp. 823-829 ◽  
Author(s):  
B. Wei ◽  
K. Komvopoulos
Keyword(s):  
Amorphous Carbon ◽  
Friction And Wear ◽  
Carbon Film ◽  
Film Surface ◽  
Carbon Films ◽  
Film Structure ◽  
Friction Behavior ◽  
Surface Microtopography ◽  
Carbon Overcoats ◽  
Magnetic Recording Heads

The friction and wear micromechanisms of amorphous hydrogenated carbon films were investigated experimentally using commercially available thin-film rigid disks with sputtered carbon overcoats and Al2O3TiC magnetic recording heads. Continuous sliding tests demonstrated the existence of two distinct friction and wear regimes characterized by different dominant micromechanisms. Scanning electron microscopy and Raman spectroscopy revealed that the evolution of friction in the first regime is due to changes of the surface microtopography and the film structure from amorphous carbon to polycrystalline graphite. Atomic force microscopy showed that the topography changes result from asperity nanofracture leading to the gradual removal of carbon material and the generation of ultrafine wear debris. The friction behavior in the second regime is due to various wear processes arising on the carbon film surface. High friction promotes surface micropitting and the formation of significantly deeper and wider texture marks. The erratic fluctuations of the friction force and microplowing of the carbon film at steady state are attributed to the relatively large wear particles generated by micropitting.

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

Warm and freeze-fracture of cotton seed radicles

1987 ◽  
Vol 45 ◽  
pp. 984-985
Author(s):  
E. L. Vigil ◽  
E. F. Erbe
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
Fracture Surface ◽  
Membrane Structure ◽  
Room Temperature ◽  
Freeze Fracture ◽  
Longitudinal Axis ◽  
Fracture Plane ◽  
Cotton Seeds ◽  
Condensed Water

In cotton seeds the radicle has 12% moisture content which makes it possible to prepare freeze-fracture replicas without fixation or cryoprotection. For this study we have examined replicas of unfixed radicle tissue fractured at room temperature to obtain data on organelle and membrane structure.Excised radicles from seeds of cotton (Gossyplum hirsutum L. M-8) were fractured at room temperature along the longitudinal axis. The fracture was initiated by spliting the basal end of the excised radicle with a razor. This procedure produced a fracture through the tissue along an unknown fracture plane. The warm fractured radicle halves were placed on a thin film of 100% glycerol on a flat brass cap with fracture surface up. The cap was rapidly plunged into liquid nitrogen and transferred to a freeze- etch unit. The sample was etched for 3 min at -95°C to remove any condensed water vapor and then cooled to -150°C for platinum/carbon evaporation.

Structure of nitrogenated carbon overcoats on thin-film hard disks

1997 ◽  
Vol 33 (6) ◽  
pp. 4551-4559 ◽  
Author(s):  
L. Huang ◽  
Y. Hung ◽  
S. Chang
Keyword(s):  
Thin Film ◽  
Hard Disks ◽  
Carbon Overcoats ◽  
Nitrogenated Carbon

Annealing in water vapor as a new method for improvement of silicon thin film properties

2006 ◽  
Vol 352 (9-20) ◽  
pp. 955-958 ◽  
Author(s):  
S. Honda ◽  
A. Fejfar ◽  
J. Kočka ◽  
T. Yamazaki ◽  
A. Ogane ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
New Method ◽  
Silicon Thin Film ◽  
Film Properties

Frequency and transient response of yoke flux for 45/55 NiFe and CoTaZr thin film write heads

1999 ◽  
Vol 35 (5) ◽  
pp. 2508-2510 ◽  
Author(s):  
J. Jury ◽  
P. George ◽  
J.H. Judy
Keyword(s):  
Thin Film ◽  
Transient Response ◽  
Write Heads

Liquid-Mediated Adhesion at the Thin Film Magnetic Disk/Slider Interface

1990 ◽  
Vol 112 (2) ◽  
pp. 217-223 ◽  
Author(s):  
B. Bhushan ◽  
M. T. Dugger
Keyword(s):  
Thin Film ◽  
Normal Load ◽  
Water Film ◽  
Adsorbed Water ◽  
Disk Surface ◽  
Adhesive Force ◽  
Contact Duration ◽  
Asperity Contacts ◽  
High Concentrations ◽  
Magnetic Recording Heads

The adhesive force between magnetic-recording heads and thin film disks in a direction normal to the interface has been measured for a variety of loads, contact times, separation rates, and relative humidities with and without a layer of perfluoropolyether lubricant at the interface. At low humidities, the adhesive force due to the lubricant film alone is small for the lubricant thickness and disk surface roughness used. We find that the major component of the adhesive force between the slider and the disk in humid environments may be attributed to an adsorbed water film which can displace the lubricant (if the disk is lubricated) at sufficiently high loads, during tangential sliding, or after extended exposure to high concentrations of water vapor and create menisci around individual asperity contacts. The adhesive force was found to increase with contact duration on the unlubricated disk, but was essentially independent of contact duration on the lubricated disk. For both lubricated and unlubricated disks, the adhesive force increased with increasing relative humidity and loading rate, but was independent of applied normal load.

Tribological implications of solvents in dip-coating lubrication of thin film magnetic disks

1996 ◽  
Vol 32 (5) ◽  
pp. 3699-3701 ◽  
Author(s):  
C. Gao ◽  
Y.C. Lee ◽  
J. Chao ◽  
M. Russak
Keyword(s):  
Thin Film ◽  
Dip Coating ◽  
Magnetic Disks
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