Surface layers with overall thickness <∼300 nm were produced by ion implantation of N+ or N2+ at energies of 50 or 100 keV in 99.99% pure aluminum. These surfaces were characterized by scanning and transmission electron microscopy, Auger electron spectroscopy, Rutherford backscattering, nuclear reaction analysis and particle-induced X-ray analysis. At doses above 2×1017 N2/cm2 , blistering of the surfaces was observed along with a reduction in the extent of the coulometric dose retained by the material. Oxygen is believed to be introduced into the near-surface region by a process of reaction and ion-beam mixing, as well as possible CO contamination of the beam. A phase, isostructural with AlN, forms semi-coherently with parent aluminum grains, however, some fraction of the metallic aluminum phase remains in the reaction layer, even at overall nitrogen contents which exceed the stoichiometry of AlN.

Electron chanelling linewidth changes in aluminum have been measured as a function of dose for boron and aluminum ion implantation. Weak beam TEM observations assist interpretation of the results by showing the nature and degree of the damage. For self implantation, a linear relationship between dose, linewidth, and dislocation density has been found up to 3×1017ions/cm2. For boron implantation, a new point-like defect appears at the higher boron concentrations, giving a much slower increase of chanelling linewidth with dose above l×1016 ions/cm2. Boron interaction with the damage stabilizes higher damage acumilations than for sel f-i mpl antati on.

An Fe-i % C alloy has been implanted at approximately 600 °C with V to a fluence of 5 × 1017 ions/cm2 and with Nb to a fluence of 3 × 1017 ions/cm2. For both implantations, Auger analysis showed that a nominally stoichiometric metal carbide layer formed beneath the surface. Below this layer, which was depleted of Fe, the metal carbide concentration decreased gradually, giving a continually graded interface with the bulk. TEM analysis showed a continuous layer of fine-grained VC or NbC, which displayed a preferred Baker-Nutting orientation relation with the underlying a-Fe matrix.

The dual ion implantation of Ti and C into 304 stainless steel has been found to reduce friction and wear in ultrahigh vacuum (UHV). The implantation treatment producing this result, 4.6 × 1017 Ti/cm2 (180 keV) followed by 2.0 × 1017 C/cm2 (50 keV), produced TiC precipitates dispersed in an amorphous surface layer. Friction and wear track compositions were measured in situ with a scanning Auger microprobe without removing the pin from the track. This treatment decreased the friction coefficient from 1.2 to 0.6–0.8 and the wear track width from 342 μm to 225 pm after 1000 cycles. Relative to unimplanted 304, wear tracks formed in UHV and air on implanted ‘304 had more N and less C. Oxygen and the metallic elements were similar in concentration, except for the presence of implanted Ti. Friction coefficients measured in air were less than those in UHV; track composition suggests that oxides or adsorbed moisture helped lower the friction in air.

Model solute distribution studies have been performed in N-implanted Fe. Concentration-verses-depth profiles have been determined by secondary ion mass spectroscopy for Fe implanted to low fluences with isotopes 13C at 190keV and 15N at 180keV followed by 14N to high fluences. At N fluences greater than 2.5 × 1017 /cm2 dramatic changes in the 13C and 15N profiles are observed. It is proposed that these changes are caused by the lattice dilation due to precipitation of iron nitrides.

A study has been made on surface mechanical properties of Ti+-implanted Fe-Cr alloys with various Cr concentrations. The implantation was performed in the dose range from 1 × 1016 to 3×1017 Ti+/cm2 at the energy of 150keV. As the Cr concentration becomes lower, the friction coefficient of implanted alloys decreases, although the increase in the surface hardness is not obvious. XPS spectra show that the implantation caused the invation of carbon to form Fe-Cr-Ti-C metastable alloys containing chromium and iron carbides. It is concluded that Ti +-implantation is useful for decrease in friction of Fe-Cr alloys with the lower Cr concentration.

A study has been made of incorporations of carbon and oxygen into surfaces of fourteen kinds of specimens during titanium implantation by means of AES sputter depth profiling. The specimens used were Fe, Al, Cu, Si, Cr, Ta, Co, Ni', Mo, Ti, Au, Pt, Pd and Fe-4.5at%C, which were implanted with titanium to a fluence of 2×1017 ions/cm2 in a vacuum of ∼2×10−4 Pa at room temperature. The fourteen kinds of specimens implanted with titanium were classified into three groups according to the amounts of incorporated carbon and oxygen from a vacuum to the surfaces. The first group corresponds to Fe, Ni, Co, Al and Fe-4.5at%C, in which surfaces a large amount of carbon is incorporated. The second group corresponds to Al, Ti and Ta, in which surfaces a large amount of oxygen is incorporated. The third group corresponds to Cu, Si, Cr, Mo, Au, Pt and Pd, in which surfaces carbon and oxygen are little incorporated. In the cases of Cu, Au, Pt and Pd, little incorporations of carbon and oxygen are caused by the high sputtering yield and the less adsorptive power of the specimens.

The article is an account of the development of a new technique to improve the surface properties of materials by ion beam bombardment combined effect of ion implantation and ion beam mixing.

Ti+ ion beam has been used to mix the surface of Cr-deposited on to Fe or to implant Ti+ into the surface of Fe. By comparing the electrochemical properties, it has been shown that the corrosion resistance of Cr-deposited Fe surface mixed with Ti + ion beam is much better than that of Ti+ ion implanted Fe surface, the critical current density Ic and minimum anodic passive current density Im are decreased by one order of magnitude in deacrated 1M CH3 -COONa-CH3 COOH solution (pH 7.3, 25°C). AES and SIMS observation show Nhat the gombined effect of implantation and mixing has been really achieved.

Ti+ ions were implanted to high fluences (up to 5 × 1017 /cm2 ) into Si3N4 substrates heated to around 900°C. Composition vs depth profiles were obtained by RBS (in conjunction with RUMP analysis) and microstructures were examined by TEM. At a fluence of 4 × 1017 /cm2, the Si concentration was considerably reduced at the Ti peak depth but enriched near the surface. By 5 × 1017 /cm2, Si was nearly depleted from the implanted layer, leaving a Ti-rich nitride layer merging continuously into Si3N4. TEN detected TiN precipitates up to several pm in diameter, and coherent with Si3N4 crystallites. A Si-Ti-N ternary phase diagram is used to interpret the observed solid state reactions.

Wear properties of Li+, K+, C+, Cl+, and Ti+ implanted glassy carbons (GC) have been studied by wear tests using silicon carbide abrasive paper. It has been found that ion implantation is effective for improving wear resistance of GC. The measurements of Raman spectra revealed formation of an amorphous structure on the surface. Anomalous depth profiles with flat concentration distribution of Li and K atoms were observed by a secondary ion mass spectroscopy (SIMS). In conclusion. the formation of an amorphous structure seems to explain the improvement in wear resistance.

Implanted glassy carbon (GC; 50 keV, 1016 N+ cm-2) is reported to be 400 times more wear-resistant to 1 μm diamond polishing than unimplanted GC. A number of samples were implanted with 15N to produce the modified surface layer and to allow a very high sensitivity measurement of wear, using the 15N(p, α)12C nuclear reaction.

Optical interferometric wear measurements are also reported. Samples implanted with 1 MeV N to 1015 ions cm-2 indicated that the enhanced wear-resistance is correlated with the nuclear energy loss density within the ion range. Mechanisms likely to be responsible for the enhanced wear resistance are also discussed.

Prompted by the recent discovery that the heavier inert gas atoms implanted into metals precipitate in the solid phase, indicative of very high pressures (,>,1 GPa), the present paper discusses the conditions under which such pressures might be expected. The metal/inert gas results are briefly described and then used as a model to show that the two essential features apart from low or moderate metal temperatures, are the insolubility of the implanted species in the host matrix and its precipitation on a very fine scale. This combination suppresses the bias-driven cavity swelling that would otherwise control vacancy acquisition in an irradiation environment.

The extrapolation to other combinations of implanted ion and metal will be discussed. Where the implanted ion is insoluble and precipitates on a scale similar to the inert gas atoms, exact analogy suggests that the precipitates will again be under high pressure. The formation of high pressure phases might not be unexpected and could be a factor in explaining the presence of phases previously thought to be metastable.

The precipitation of Kr injected into Ni at temperatures between 25 and 560 C has been studied with transmission electron microscopy. The Kr precipitates in cavities which increase in size with Kr fluence. Electron diffraction and dark-field imaging demonstrate that small Kr precipitates are solid, fcc crystals aligned with each other and the Ni lattice. The Kr is held in the solid state by the pressure generated by the cavity walls, and this pressure decreases with increasing cavity size. The mismatch between the Kr and Ni lattices is as large as 55%. The average Kr lattice parameter, determined from electron diffraction at room temperature, increases with increasing Kr fluence from 0.515 nm to an asymptotic value of about 0.545 nm for implantations at temperatures of 300 C or less. This increase towards an asymptotic limit is due to expansion of the Kr lattices as precipitates grow, until the decrease in cavity pressures allows melting of solid Kr in large cavities. Diffuse electron scattering was observed from liquid Kr in large precipitates for fluences greater than 5·1020Kr+m−2. Implantations at temperatures of 400 C or higher result in a bi-modal size distribution containing small solid precipitates and an additional population of larger, faceted precipitates, a larger average Kr lattice parameter for a given Kr fluence, and a higher asymptotic lattice parameter of 0.550 nm. Solid Kr seems to inhibit motion of small precipitates, and Kr melting is a precursor to faceting and growth by coalescence.

Gas desorption spectrometry has been used to study the behavior of implanted noble gas ions in silicon. Results of low dose Ar implants followed by thermal desorption has shown the release of argon in Si from distinct surface related trapping sites, from substitutional argon (ArV) and from larger Ar-V clusters. This information gives an insight into the response of the silicon lattice to the Ar implants. For higher Ar doses, the effects of amorphization are clear in the desorption spectra and lead tò a method of measuring the recrystallization velocity during epitaxial regrowth (v=2×106 exp(−2.8 eV/kT). A similar value was found for thin sputtered Si films. The paper discusses high dose Ar saturation phenomena and describes the use of helium implants to probe defects and defect structures, such as bubbles and voids, in silicon.

Uranium intermetallics are under consideration as possible low-enrichment reactor fuels. These materials divide into two classes with regard to dimensional stability during their service lifetime: those which suffer extreme dimensional growth and those which do not. It has been suggested that the rapid-swelling materials are those that become glassy under irradiation while the low-swelling materials are those that remain crystalline. The structural and dimensional stabilities of U3Si (depleted uranium) have been investigated as a function of temperature duning Kr irradiation by in situ. HVEM observations. Below 550 K, this material becomes glassy during 1.0 MeV Kr irradiation. Prolonged irradiation at 475 K also leads to rapid darkening of the TEM bright field image of the specimen, growth of the initial perforation at rates which far exceed those due to sputtering, and formation of additional thin areas and holes. Irradiation at 615 K does not result in observable image darkening or rapid growth of the initial perforation. After 2×1020 Kr m-2, the crystalline material irradiated at 615 K is stabilized against subsequent ion-irradiation-induced amorphization and growth at 475 K. Similarly, after 2×1020 Kr m-2 at 475 K, the glassy phase persists at 620 K under additional Kr irradiation, and the rapid growth continues. The mechanism of the irradiation-induced growth of the glassy material does not involve gas precipitation but rather may involve deformation by viscous flow assisted by the defects generated during irradiation.

Dramatic implantation-induced changes in the Raman and infrared spectra of polycrystalline samples of La2CuO4-y are reported for implantation of Sr in the fluence range 0.5 to 1.5 × 1016/cm2. The Raman and ir-reflectance spectra of the Sr implanted material reveal disorder-induced lines corresponding to breakdown of selection rules and to non-zone-center phonon modes. Whereas the main features in the Raman spectra of the implanted sample are broad disorder-induced lines centered at ∼ 560 ± 5 cm−1, reststrahlen lineshapes are observed above ∼ 800 cm−1 in the ir-reflectance spectra. After thermal annealing (550°C), the multiphonon lines in the ir spectra diminish, and the disorder-induced lines in the Raman spectra split to form well-resolved, sharper lines at 530 and 580 cm−1, identified with maxima in the phonon density of states. The sensitivity and complementarity of Raman and infrared spectroscopy to implantation-induced disorder and subsequent partial recovery by thermal annealing suggest that these techniques can be used to characterize sensitively disorder in ion implanted La2CuO4-y high Tc, materials.

The computer program MARLOWE has been used to investigate low energy boron implantation into silicon. When implanted in a “random” direction at 5 keV, the most deeply penetrating ions are seen to have spent an appreciable part of their path travelling in <001>, <011> or <112> axial directions or in {111} or {220} planar channels. Channeling was then investigated more directly by observing the mean path travelled by the ions in the direction of incidence as a function of both azimuthal and tilt angles between the direction of incidence and the 001 direction. At 5 keV, {111} planar channeling and <110>, <112>, <111> and <100> axial channeling is prominent, with {220} planar and <310> and <114> axial channeling observed to a lesser degree. Higher order planar channeling such as {400}, {331}, {422} or (511} was not observed at 5 keV. At 0.75 keV only <110>. <100> and <112> axial channeling and {111} planar channeling remained.

The damage and annealing behavior of <100> Si implanted at room temperature by and P+ at different energies (5-600KeV) and intermediate dose (∼1014/cm2) has been investigated. Experimental results show that the damage created by implantation is always greater than that of P+ implantation. The ratio of total displaced atoms of the target cuased by molecular and atomic implantation, ND(mol)d/ND(atom) reached a maximal value at 100KeV () and 50KeV (P+) after rapid thermal annealing, the carrier concentration profiles measured by spreading resistance measurements are also different for the and P+ implanted samples. We attribute essentially this phenomenon to the displacement spike, but the multiple collision effect and the interaction between two molecular fragments should be considered while the incident energy is high.

The effect of N2+ ion implantation in ∝-Fe2O3 has been investigated by means of Conversion Electron Mossbauer Spectroscopy (CEMS). It Is shown that at a dose value of 1×1017 ions/cm2 and 3×1017 Ions/cm2 the samples exhibit new Interesting hyperfine features which can not be ascribed to known oxide or nitride phases. It Is thus concluded that Iron Oxynitrlde Is formed by the nitrogen Implantation process.

The influence of As+-ion implantation on the oxidation of TiSi2 films is investigated. It will be shown that implantation leads to a greatly increased rate of oxidation in a dry O2 ambient. Low-temperature oxidation of the implanted films not only results in substantial oxidation of the films, but completely alters the films' morphology. Different implantation techniques were used to isolate the effects of ion-induced damage from chemical effects, so that each could be separately studied. It will be shown that neither chemical nor damage effects are able, by themselves, to account for the enhanced oxidation. Rather, a model is proposed to explain the role of implantation in the oxidation process which depends on a synergistic relation between these two effects.