Application of surface analysis to lubrication problems

Classified

4592. X-ray

abstracts

Preferential photoelectron

4592-4598

sputtering in oxides spectroscopy. (USA)

as metals

and

revealed

36 by

The surface film on an oxidized multicomponent alloy usually contains a number of metallic and oxidized phases. During depth-profile analysis, such metal and oxide phases can be differentiated by X-ray photoelectron spectroscopy (XPS), provided the surface oxides are sufficiently stable to withstand ion bombardment without decomposition. A quantitative analysis of the surface composition, however, is not possible without taking account of the effects of preferential sputtering of some phases. We have investigated the effects of 3 keV argon ion bombardment on the composition of oxide-free surfaces of iron-nickel and iron-nickellO%) compared with the bulk compositions. In the composite metal-oxide mixtures studied, depletion of the metallic phase is significant in some cases and must be taken into consideration in a quantitative depth profile. (Canada)

N S McIntyre 802.

and F W Stanchell,

J Vat Sci Teclvrol,

16 (2), 1979, 79% 36

4593.

Preferential

sputtering

of Ta,OS

by argon

ions. (USA)

X-ray photoelectron spectroscopy has been used to show that Ar+ preferentially sputters 0 from the surface to TalOs. In addition, X-ray photoelectron, Auger electron, ion scattering and secondary ion mass spectroscopies were used to show that more reduction of Ta20s is caused by 0.5 keV Ar+ than by 5 keV Ar+. This dependence of preferred sputtering upon energy is attributed to changes in the sputtering mechanisms.

P H Holloway 796.

and G C Nelson,

J Vuc Sci Techno/,

dose in GaAs(ll0)

The change in short-range order with sputter dose a GaAs (1 IO) surface is followed by measuring the of diffraction spots in low-energy electron diffraction In particular, step densities and the step height Evidence for structural damage beyond the creation interpreted in terms of coherent domains of limited

D G Welkie 788.

and M G Lagally,

J Vuc Sci Tec/wo/,

and annealing of angular profiles from the surface. are determined. of steps can be size. 16 (2). 1979, 784-

36 4595. Model of ion knock-on interface studies. (USA)

mixing

with

S A Schwartz

4596. (USA)

and C R Helms,J

Preferential

Vuc Sci Tecl~nol,

sputtering

in gold-nickel

to examine of ion enerev results a;

16 (2), 1979,781-783. 36 alloys.

and gold-copper

The preferential sputtering of three alloys of gold and nickel and five alloys of gold and copper is studied. Binary alloys containing 626 at. 0; nickel and 6-57 at. 74 copper were used. Samples were scribed Lr sirrc to avoid the complication of a surface oxide film. For Ni/Au with an ion energy of I keV. the gold was sputtered preferentially leaving a nickel-enriched surface. For the 6% alloy the amount of enrichment was somewhat less than is predicted from pure element sputter yields, whereas for the other two alloys the enrichment is slightly higher than predicted. The thickness of the altered layer appears to be in the 50-75 8, range. For Cu/Au, very little preferential sputtering was observed. H G Tompkins, J Vat Sci Tecl~t~ol, 16 (2). 1979, 778-780.

36 4597. Application

of surface

analysis

to lubrication

problems.

(France) During friction of lubricated contacting surfaces, and with a thickness of the oil film inferior to 200 nm, anti-wear solid films are created on the worn surfaces. When there is dry friction, transfer films occur, with an inorganic structure in the case of polymers. To solve the different problems inherent to tribology, both mechanical and analytical studies are necessary to determine film compositions. A general survey on the question is presented. The application of AES/SIMS analysis to determination of the nature of films is particularly developed. J M Georges et al, Vide, 34 (197). 1979, 163-197. (it1 French)

16 (2), 1979, 79336

4594. Correlation of short-range order and sputter using a vidicon-based LEED system. (USA)

have also performed Auger sputter profiling experiments the broadening of the Si-SiO, interface as a function for Ne+, Ar+>nd Xe+ bombardment. The experimental consistent with the mixing model.

application

to Si-SiO,

We have developed an ion knock-on mixing model which yields quantitative predictions of the broadening observed in sputter profiling experiments. The model is based & an analogy ;o theimal diffusion theorv. Interface widths and oeak widths are seen to broaden in an’rms fashion with a broadening factor W which is inversely proportional to the square root of the sputtering yield. We

IV. Materials and vacuum technology 42. GLASS, ELASTOMERS, LACQUERS,

4598. (USA)

Grease

CERAMICS, WAXES, PAINTS,

lubrication

Greases have been developed turbo-molecular pumps of I year without regreasing. pared with lubricating oil tamination of the evacuated eliminates need for cooling and inverted positions are heating, hot degassing and

G E Osterstrom 747.

techniques

REFRACTORY LUBRICANTS, OILS.

of turbomolecular

used OXIDES, CEMENTS,

vacuum

in PLASTICS,

42 bearings.

pump

within the past 5 years which moderate rotor speeds to operate The relative immobility of grease greatly decreases the probability space by operator error. Low most applications. Horizontal, practical. Special problems of gas rough transport are discussed.

and T Knecht,

J Voc Sci Techrol,

16 (2),

enable at least as comof confriction vertical friction

1979, 746-

355