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Measurements of He release were performed on Ni samples doped by thermal neutron irradiation or ion implantation. Closed and open cylinders of Ni were neutron irradiated at 100°C. The amount of He released into the interior of the closed cylinders was equivalent to that produced in the volume of Ni within about 0.5 μm of the surface, indicating some mobility of He at room temperature. The open cylinders were heated in vacuum while the He release was measured. Below 1000°C, the amount of He released was equivalent to that produced within 0.02 μm of the surface. Surface evaporation could account for the He release at higher temperatures. Upon melting the Ni, all the remaining He (about 98% of the amount introduced) was released. He release from Ni at temperatures between 18 and 600 K was measured after ion implantation of 35 keV He+ at 18 K. The only significant release was sharply peaked near 50 K. (A previously reported release near 150 K was probably an artifact related to the experimental techn...

In the system of boron and carbon, the formation of boron carbide was investigated after ion implantation of 25 keV B ions into carbon or of 25 keV C ions into boron and subsequent annealing. TEM and electron diffraction studies showed that the crystallization of boron carbide begins only at temperatures above 1050°C. By implantation of 20 keV C ions into iron (ion dose 1017 C ions/cm2) only the metastable e-Fe2O will be generated, which at above 220°C transforms into the stable cementite Fe3C. After implantation of 20 keV B ions into iron, no formation of iron boride could be found. These experimental facts can be understood qualitatively with the help of the thermal-spike model. The energy density or the temperature in the thermal spikes is not sufficient for the generation of cementite iron boride or boron carbide.

The effect of the implantation of ions of various natures (N, O, Al, Tl) in ZnTe crystals has been investigated by means of electrical and optical techniques. We show that ion implantation as well as sputtering leads to generation and migration of electrically active defects over thousands of Angstroms or microns farther than the projected range of the implanted ions. Anneals in saturated Zn vapour allow (1) the disappearance of most of the implantation defects at 300–400°C (2) the formation of a new compensated zone by surface generation and migration of intrinsic donor defects (or out-diffusion of the native acceptors) in the 500–550°C range. The temperature at which the implanted ions go into substitutional lattice sites and the nature of the defect- impurity interactions is a particular problem for each ion. The case of the cathodoluminescence efficiency of implanted Al ions is more particularly investigated.

The effect of implantation induced radiation damage on the oxidation of aluminium has been studied using implanted krypton. Annealing studies have revealed a complex recovery process tentatively ascribed to the repair of point defects, dislocation loops and subsequent grain growth. Higher dose (1O17 ions cm−2) xenon implants resulted in implant out-diffusion and surface exfoliation during annealing.

The effect of oxygen plasma exposure on the motion of mobile ions in SiO2-Si structures has been investigated. The ion transport was found to be limited by ion traps at the outer surface. A plasma-induced mobilization effect was observed only at 300°C substrate temperature during plasma exposure. At lower temperatures some interrelation of Na and H ions is suggested based on the behaviour of the different charge centres. Der Einfluβ der Sauerstoffplasmabehandlung auf den Transport von beweglichen Ionen in SiO2-Si Strukturen wurde untersucht. Der Ionen Transport wird durch Haftstellen an der SiO2- Oberfiache bestimmt. Es wurde festgestellt, das eine Aktivierung der beweglichen Ionen wahrend Plasmabehandlung nur bei Substrattemperatur von 300°C auftritt. Bei niedrigen Temperaturen nehmen wir an, das eine Zusammenhang zwischen Na- und H-Ionen existiert, die auf Grund des Verhaltens der verschiedenen Ladungszentren erlautert wird.

The analytical expression for the sputtering yield of fine-grained targets by heavy multicharged ions derived previously by the authors is discussed. Experimental yields are given for the sputtering of fine-grained islet-like gold layers and for bulk gold foil by 45–65 MeV fission fragments. A comparison of the experimental yields with those obtained by calculation is made. Existing models of sputtering of targets by heavy multicharged ions are considered. Some assumptions on the sputtering mechanism are made.

An accurate method for measuring the single-scattering cross section of ions on solid targets is described and used for 14–31 MeV 81Br ions scattered through 3–12° on gold targets. The results agree with the theory of Lindhard, Nielsen and Scharff except for the lowest t ½ values, where a small deviation is observed. Comparing the present data with earlier published measurements of 0.3–2 MeV H, He, and Li ions scattered on selenium and gold, we conclude that the theoretically predicted scaling laws are fulfilled in the region of weak screening of the Coulomb interaction.

Absorption and emission measurements of the 4A2-2E transitions of Cr3+ in GdAlO3 at T iU4.2 K, in magnetic fields up to 6 T parallel to the easy axis, are consistent with a magnetic Franck-Condon principle for which the energy difference between the absorption and emission lines arises mainly from the spin relaxation, rather than the neighboring ion space coordinates around the impurity. The Cr-Gd exchange-coupling const. changes with the applied magnetic field from J = 2.1 cm-1 at H = 0 to Jsat = 1.46 cm-1 at high field.

Ion-implantation range distributions in inhomogeneous media are calculated with angular deflections included in the P 1 approximation. The calculations assume power cross sections and neglect electronic stopping. The natural length scale found earlier in the path-length approximation is shown to be general. Attention is concentrated on a two-medium target, but the method may be generalized in an obvious manner to any number of layers of different target media. Results are more explicit when the source and the interface coincide, and are examined in greater detail when the medium behind the coincident source and interface is the vacuum. In this case the mean range within a semi-infinite medium and the reflection coefficient are calculated. The results are expected to be valid for slow light ions on a heavy-atom target. The reflection coefficient is in good agreement with earlier calculations when the target-atom/projectile mass ratio is large.

Aluminium single crystals have been implanted with S, Ca, Cu, Ga, Ge and Cs ions with energies corresponding to similar projected ranges. Energy dependent channelling and Rutherford backscattering experiments have been performed in the energy range of 1–3 MeV using 4He+ ions as the analyzing particles. The aligned spectra of Cu, Ga, Ge and Cs implanted samples showed a monotonous increment of the dechannelling yields with depths and no disorder peaks have been observed. The dechannelling yields determined from these spectra revealed a √E dependence with a relatively higher slope for the Cs implanted sample compared to the others. The Ge implanted sample showed very little dependence on √E. However, the spectra of the S and Ca implanted samples showed disorder peaks within approximately the measured projected range as the energy of the analyzing beam was increased. The lattice positions of these ions in Al are also reported. S, Ca, Cs and Ge showed no or little substitutional occupation, however, ...

The mechanism of mixed dimer negative ion formation in the gamma radiolysis of the gaseous system hydrogen sulphide-methyl bromide has been investigated using carbon tetrachloride and chloroform as the electron scavengers. The concentration of methane was measured gas-chromatographically. The measurements were performed at different total pressures. ΔG(CH4)-1 is a linear function of [CH3Br][H2S]2/[Sc] (where Sc═CCl4 or CHCl3). On the basis of the above dependencies the mechanism of the formation of the (CH3Br-H3S)− ion was confirmed and the rate constant was calculated to be k=K-ka-kc/ka = 6.5 ×l0−49 cm9 molecule −3s−1

The influence of ionization density on the annealing properties of silicon layers implanted with 1.2 × 1014-l × 1015 cm−2 of phosphourus ions has been studied. The ionization background was created by high energy electrons from a Van de Graaff accelerator with the beam density on a sample in the range of 2.5–25 μA/cm 2. The dependence of the crystallization growth rate vg on the e-h recombination rate has been observed. An exponential dependence of the growth rate vg on the ionization density was observed for amorphized and nonamorphized Si layers. No change of the activation energy Ea . in the used beam density range was noticed.

The Z1-range oscillation amplitude is investigated as a function of energy for Eu, Yb and Au ions implanted in amorphous Si at energies from 10 to 390 keV. The obtained experimental results are not reproduced by the recent theoretical predictions of Burenkov and collaborators, showing large discrepancies for energies lower than 50 keV.

Channeling effect measurements using MeV He ions were used in the study of 80 keV, R.T. arsenic implants in silicon. The implantation disorder and the atom location of arsenic atoms were studied as a function of sequential anneals in the temperature range 600-900°C for the doses 0.7, 1.5 and 4 × 1014cm−2. Values for the amorphization dose, average damage depth and spread of damage depth are reported and discussed. From the atom location measurements, it appears that no appreciable arsenic fraction is present at regular tetrahedral interstitial sites in the silicon lattice, following different isochronal (30 minutes) annealing steps at temperatures ranging from 600° to 900°C. The arsenic substitutional fraction was determined and the data correlated with conductivity and Hall effect measurements previously performed for the implantation dose of 0.7 × 1014 ions - cm−2. The results of the analysis seem consistent with a model for the physical process responsible for the electrical activation of impl...

The sputtering of polycrystalline Ag and Au by heavy atomic and molecular ion bombardment has been measured as a function of the ion beam angle of incidence, θ Comparison is carried out between the measured and calculated values where the calculated values are based upon determination of the surface deposited energy assuming infinite (transport theory) and semi-infinite (Monte-Carlo calculation) media. It is found that the angular dependence, out to 75° from normal incidence, of the measured sputtering yield for Ag and Au bombarded with heavy atomic and molecular ions of Sb and Bi are somewhat different, with the Ag sputtering yields showing a slower rate of increase with θ at large (θ ≳ 70°), than in the case of Au sputtering. Also the sputtering by molecular ions shows a much larger sputtering yield/atom than for the same velocity monatomic bombardment. This enhancement increases non-linearly with the number of atoms/molecule, but decreases with the angle of incidence. It is found that the sput...

Radiolysis of the trisoxalato cobalt (III) ions in deoxygenated neutral aqueous medium have been undertaken at low and high doses. At low doses, the rate of radiolysis is independent of the concentration of the complex ion in the range 3.24×10−3 − 10−2 mol dm−3 and is enhanced by the addition of free oxalate ions. On prolonged irradiation, the rate of degradation gradually increases. Initially H and reduces the complex ion, but at later stages, oxalate ion radical C2O4 ·1−, produced by the interaction of OH radicals with the generated C2O4 2− ions during the radiolysis, also reduce the [Co(C2O4)3]3− ions.

A computer code previously set up to simulate ion penetration in amorphous solids has been extended to handle with recoil phenomena. Preliminary results are compared with existing experimental data.

Although the average composition change resulting from O or N implantation in a metal is small up to a dose of about 3 × 1016 ions/cm2, the implanted atoms tend to be atomically mobile under the conditions used for bombardments and precipitation of an oxide or nitride can be expected. The object of this work is to explain what phases are formed. One model is based on the postulate that the precipitates are at the surface and have a high anion-to-cation ratio. The resultant phase therefore tends to be that which arises from the impact of any heavy particle on the surface of a high oxide or nitride. An alternative model is based on the postulate that the precipitates tend, independently of where they form, to be in qualified thermodynamic equilibrium with the metal. A consideration of the known examples of O or N implantation suggests that qualified thermodynamic equilibrium is the better guide to which phases are formed.

Measurements of the depth profiles of disorder and the depth integrated disorder produced in Si at 40 K or 300 K by low energy (15 keV-60 keV) ions of a range of masses from the light (N+ and P+), intermediate (Ar+ and As+) to heavy (In+, Sb+, As+ 2, Bi and Sb+ 2) were made using Rutherford scattering-dechannelling techniques. Studies of both the ‘surface peak’ disorder and the dechannelling minimum indicate a gradual change in the process of disorder production from one of point defect generation for light projectiles to direct impact amorphisation for heavy projectiles. In the lower mass ion cases it is concluded that amorphisation is produced by overlap of more lightly disordered regions and it is shown how all the data can be encompassed within a generalized model of amorphousness production which occurs when local defect densities lie in the range 2–18%.

Channeling measurements by proton-induced X-ray emission have been made on ⟨111⟩-oriented silicon covered with evaporated layers of carbon, copper and gold to investigate the dependence of minimum yield on both energy and film thickness. The energy range was 80–300 keV and the thickness range was 5–60 nm. Minimum yields are calulated by applying Meyer's treatement of plural scattering and probability curves determined from (i) a step function approximation and (ii) a gaussian function approximation to the azimuthally averaged probability curves are in good agreement with experimental results for gold. For carbon layers and thin copper layers a good agreement is only reached for the averaged angular yield profiles. From the results follow, that a step function approximation to the angular yield profile is only applicable if the half width in the pural scattering distribution of the ion beam after passing the film is greater than the critical angle for channeling.

Bombardment of a clean Ta target by 4 keV Cs+ ions under ultra high vacuum (UHV) has been experimentally shown to give rise to photon continuum emission by sputtered products.

The formation of ethers in radiolysis of methane, ethane, and propane in the presence of either methanol or ethanol was studied in the gas-phase using a conventional approach based on analysis of the stable products. A mechanism is established to be ionic and probably involves condensations of ions originating from alkanes with alcohols, solvation of ionic complexes by alocohols, and finally supersession of ethers by alcohols in equilibrium exchanges. For want of mass spectrometric data the identity of ionic precursors remains speculative, although there is strong evidence that C2H5 + ions are not involved. In propane another ionic mechanism contributes to the formation of C2H5O-n-C3H7; in this case the ionic precursor originates from the alcohol rather than from the alkane.

We report measurements of the dose dependence of the sputtering of evaporated films by 30 keV ions under UHV. An initial (sub-monolayer) enhanced sputtering is attributed to the removal of weakly bound atoms; this enhancement does not depend on the incidence angle of the projectile.

Single crystals of Mo were bombarded with 86Kr, 2ONe, 11B, 4He, and 1H in such a manner that the energy deposited into elastic collisions (displacement events) in the near surface region was approximately equal for each implant. The ion fluences spanned more than two orders of magnitude, and the resulting damage level at each fluence was monitored by obtaining aligned backscattered (channeling) spectra in a axial direction. As an additional check on the channeling results selected implants were also examined with TEM. The channeling experiments clearly show that the final damage state, at all fluences, for 86Kr and 2ONe is the same. At low fluences, the final damage state for 8RKr, 2oNe, 11B, and 4He appears to be the same, but for high fluences there are unresolved difficulties with the 11B and 4He channeling results. TEM examinations indicate that there are no gross microstructural differences for 86Kr, 2ONe, and 11B and only moderate differences for 4He. Both channeling and TEM indicate ...

The relative differential sputtering yields, dS, in a fixed small solid angle at various directions from a single crystal silver target under normal Ar+ ion bombardment (ion energy from threshold to about 100 eV) have been measured. The yields measured in the directions of various sputtering “spots” were: dS 1 in the 〈110〉 direction at about 60° from the (110) face;dS 2, 〈110〉 direction, 45° from (100) face;dS 3, 〈110〉 direction, 35° from (111) face;dS 4, 〈110〉 direction, normal to (110) face; and dS 5, 〈100〉 direction, normal to the (100) face. The magnitudes of the yields were: dS 1 ≃ dS 2 > dS 3. An order of magnitude lower were: dS 4 > dS 5. For the oblique 〈110〉 emissions, the curves of (dS) 1/2 vs. incident ion energy were linear for ion energies of about 20–50 eV; extrapolation of these curves to zero yield gave the following sputtering threshold energies: dS 1, 14 eV; dS 2, 18 eV; and dS 3, 23 eV.

Parameters of relevance to ion beam lithography and ion implantation masking have been determined for two polymer resists, PMMA and Microposit 23M. These have been bombarded with 50 keV As+ at low power densities in order to avoid blister formation. Loss of volatiles was found to cease and lateral stress (in PMMA) changes from tension to compression at a critical dose of 1015 ions cm−2. These parameters were measured using a triple quartz resonator technique (TRT). X-ray photoelectron spectroscopy (XPS) data indicate a loss of oxygen in the bombarded resists by reduction of −C=O groups. The arsenic concentration, measured by Rutherford Backscattering (RBS), rose linearly with As+ ion dose with 100% retention of As+ in the resists. A dose of 2 × 1012 ions cm−2 was required for full exposure of PMMA and the developed step height was found to correlate well with calculated arsenic range data.

The channeling technique has been used to determine the disorder distributions in silicon bombarded at 45 K with a 10-80 keV H+, He+, Li+, B+, C+, N+, O+, and Ne+ (v < eI/h). Comparison of these measured distributions with calculated deposited energy distributions obtained using a Monte-Carlo technique yields quantitative data on the inelastic stopping cross-section. For random incidence we find that the inelastic stopping cross-section for silicon is larger than the Lindhard value and exhibits a Z 1 dependent variation in qualitative agreement with earlier foil transmission experiments.

The velocity-dependent interaction potential theory between fast ions and the solid atoms is developed. The theory incorporates effects of the dynamical screening, electron stripping and quantum corrections to the interaction energy due to the projectile motion. Some experiments concerning a passage of fast ions through amorphous and crystalline targets are compared with the theoretical predictions.

A review of techniques for electrical measurement of high current ion beams is presented. A computer analysis of the secondary-particle current-collection schemes is made for dosimetry-cup configurations commonly used on ion implanters with electrostatic scanning. The design of a dosimetry cup for a high current implanter with mechanical scanning is discussed. Also beam monitoring techniques for uniformity measurements are reviewed.

Two models of a thermal nature are currently advocated to explain the presence of ions amongst sputtered particles. In so far as these models are valid, one must consider the possibility that excited neutrals amongst sputtered particles also have a thermal origin, whence that the yields of photons emitted by these excited neutrals will be given by Yield α (ω i /Q) exp(-e i /kT). Here ω i is the degeneracy of a state which lies e i above the ground state and Q is the internal partition function. We have tested the above equation experimentally and can summarize the results as follows: (a) The equation was satisfactorily obeyed by Be, BeO, Al, Al2 O3, Sc, GaAs, Y, In, and Tl, the inferred temperatures lying in the interval 3600–5900 K. (b) The range of temperatures agrees with four independent estimates from other work, (c) The temperatures are, on the other hand, insensitive to the variation of target mass from 9 to 204 u, ion mass from 20 to 84 u, ion energy from 4 to 16 keV, and target crystalli...

(100) Silicon wafers implanted with 2 × 1015 31P+/cm2 at 100 keV have been annealed using a scanning beam of incoherent light. The main results obtained after annealing are: (a) the carrier concentration profile shows a complete dopant activation without diffusion of the implanted ions; (b) the values of carrier mobility are similar to those obtained by furnace annealing; (c) an improvement of minority carrier diffusion length is often observed; (d) a very good damage recovery is obtained. Transmission Electron Microscopy observations show that the residual damage is confined within a region at 0.2 μm depth and consists of dislocation loops of about 50 A diameter. It is concluded that this technique can be used to obtain very good annealing of implanted layers.

Most of the alkali halides are freely miscible with one another. The solid solubilities of fluorides, however, exist over a limited range. Thus, not more than 1.5 mol.% NaF can be added to LiF, and the maximum amount of LiF that can be accommodated substitutionally in NaF is about 8.5 mol. 96. Fate of LiF added in excess to these amounts is unknown. It has been suggested that Li+ may enter interstitially. The coloration of the solid solutions provide a clue to the position of the foreign alkali ion in the host lattice. The optical and TSL measurements on the coloured NaF:LiF samples are presented in this paper, which show that Li+ partially goes to interstitial sites, and the remaining amount forms colloids.

The morphological evolution of pyramids, developed on bombarded Cu surfaces, as a function of consecutive doses of normally incident mass-separated 12 keV Kr+ ions from 2.4 × 1016 up to 3 × 1019 ions/cm2 has been studied. Three types of polycrystalline sample, with initial surface topography due to distinct polishing procedures, were used, Three main conclusions were reached. (a) The presence on the unbombarded surfaces of asperities is very important, there being a 1:1 correlation between pyramids and pre-existing asperities, at least for the surfaces as here prepared. (b) In agreement with the predictions of Carter, Colligon, and Nobes, all pyramids disappeared at high enough doses with all specimens. Pyramids are therefore not an equilibrium structure. (c) Features with a mushroom-like (i.e. undercut) shape were observed which can, under certain circumstances, be an intermediate stage towards the final pyramidal shapes but are, more generally, an indication of the existence of what we will cal...

Yield measurements are presented for 2–10 keV He ions reflected over 30° or 60° from a (100) surface of a copper target. This yield is measured for different values of the angle of incidence and of the primary energy. The experimental results are explained by charge exchange processes occurring during the ion-surface interaction. From symmetry arguments we conclude that two types of charge exchange processes may be distinguished: (a) The ion interacts with the free electrons of the metal. This may result in an Auger-type neutralization, (b) The ion interacts with a single surface atom. This may result in ionization or neutralization, similar to that which occurs in ion-free atom collisions. A simple model, which takes into account Auger-neutralization and the ionization which results from a violent collision with a surface atom, can partly explain the experimental results. It appears that for a more complete description, the neutralization resulting from the ion-surface atom interaction must also...

The importance of homogeneous and heterogeneous nucleation in the amorphization of silicon by ion implantation is considered. Previously a homogeneous model involving dose rate had been used to identify neutral vacancy and divacancy annealing as important mechanisms in the amorphization process. In an attempt to verify this dose rate model, experiments which detect the electron spin resonance signal from the amorphous regions have been performed. Both a light ion (N+) and a heavy ion (Kr+) at low (20 keV) and high (180 keV) energy were implanted into silicon at low (80°K) and higher (∼350°K) temperatures. No dose rate dependence was found, and the temperature dependence is not as predicted by the model. In addition, the production rate is not proportional to the dose to the one-half power-a power dependence which has previously been attributed to homogeneous nucleation. Furthermore, since the data agrees with the predictions of a heterogeneous model, it is concluded that homogeneous nucleation is...

While having a similar composition to Cellulose Triacetate, Cellulose Diacetate is a less sensible heavy ions detector. With a 0.9 N potash etching at 20°C, ions which have higher Z than Carbon are not recorded and the Etch Rate Ratio is about 1 to 2 for Cu and Kr ions. The study of the infrared absorption spectra shows a decrease of the v(O-H) band intensity at 3500 cm−1 for CDA, when it increases for CTA.

Mossbauer and X-ray investigations of 3 MeV proton irradiation effects in biotite are reported. Mossbauer spectra of natural biotite samples in the temperature range from 77 K to 970 K were obtained and irreversible changes caused by heating of the biotite were investigated. Changes in the Mossbauer spectra of irradiated and heated samples were found to be similar and are interpreted as a result of oxidation of Fe2+ ions to the Fe3+ state. It is shown both by means of Mossbauer and X-ray spectroscopy that a heavy irradiation gives rise to a formation of Fe3O4 particles of a size about 0.01 μm.

Straggling of He ions has been measured in thin films of aluminium, copper and gold by the backscattering technique at energies varying from 0.25 to 0.75 MeV/a.m.u. The results are compared with the predictions of the theories of Bohr, Bethe-Livingston and Lindhard-Scharff. There is a fair agreement with the Bethe-Livingston calculations.

Subsurface disorder created by 40 keV N+ bombardment of silicon has been studied for aligned (111) bombardment at various temperatures. It is found that the little or no very near surface disorder is created by implantation, however, the deeper bulk damage production is temperature dependent.

A Fully Dynamic Rate Theory (FDRT) has been used in the computer code TRANSWELL to analyze the response of metals during steady-state and pulsed irradiations. This paper correlates the FDRT with experimental data on void growth in metals. It is shown that the theory is successful in predicting the swelling behavior of different metals over a wide range of temperatures, dose rates, bombarding particles and irradiation time structures. Swelling of 316 stainless steel, Aluminum and Nickel bombarded with heavy ions, neutrons, and electrons at dose rates varying from 10−6 to 10−1 dpa/second is studied for both steady-state and pulsed irradiations.

The scattering of quasichanneled particles on atomic chains and planes is studied by computer simulation for the crystals of chemical compounds. It is shown that quasichanneling is the specific regime of ion motion in the lattice. Its main features are: (1) a sharp increase of the backscattering probability; (2) transition of the ions from the quasichanneled component into a random one; (3) high sensitivity to the structure and the composition of the atomic “chain”; (4) dependence on the value and the direction of the atomic displacements.

We have measured sputtering yields of H2O films with 19F ions at bombarding energies from 1.6 to 25 MeV. The sputtering yield was found to be very sensitive to the incident charge state of the beam, and insensitive to the thickness of the ice film for thicknesses ranging from approximately 20 to 80×l016H2O/cm2. The yield was independent of the target substrate temperature from 10 to 60 K and independent of the F beam current density from < 1 to approximately 5.5 particle nanoamps/mm2. There are several models proposed to explain enhanced sputtering of dielectrics; we have discussed their relevance to our data.

Ion beam induced reactions of multilayered Fe/Si thin films have been studied by means of conversion electron Mossbauer spectroscopy (CEMS). A ferromagnetic amorphous layer is formed as a consequence of 300 keV xenon ion mixing of the multilayered films at room temperature. However, it is shown by the technique of depth profiling of CEMS that even in the case of coating films thicker than irradiating ion range a significant mixing occurs in the interface region between the overlayered films and the substrate. The interfacial mixing is found to lead to inhomogeneities in the distribution of Fe and Si elements and to non-uniform magnetic hyperfine field through in the mixed amorphous layer.

We have investigated annealing of ion-implanted GaInAs using transmission electron microscopy. We have found that the best condition for the post-implantation anneals for GalnAs is a 30 second anneal at a temperature of 700–800°C. This produces a material similar in character to the untreated GaInAs. Anneals for longer than 30 seconds produce crystal defects becoming increasingly complex with time for similar temperatures.

The results of experimental study of the 10–35 keV argon ion scattering by the (100) face of a copper cyrstal are presented. The results obtained are discussed in terms of the model of correlated scattering by an atom pair and a close-Dacked atomic row.

All quartz contains Al3+ ions substituting for Si4+ ions with an adjacent interstitial alkali or a proton providing the necessary charge compensation. When thermally released from their trapping sites the interstitials can migrate along the relatively large c-axis channels. Li+ is the predominant charge compensator in commercially grown quartz. If the sample is heated with an electric field applied along the c-axis the alkalis will be swept out and released either by protons or by another alkali. This electro-diffusion or sweeping process can be used to selectively dope the Al3+ site. Applied fields of approximately 15 V/cm and 3000 V/cm result in equivalent current densities for alkali ions and hydrogen respectively. Alkalis show activation energies between 0.95 and 1.4 eV; hydrogen shows an activation energy near 1.9 eV. If ionizing radiation is present, hydrogen is mobile at all temperatures; however, the alkalis only become mobile at temperatures above 200 K. A comparison of the radiation ind...

Single crystal silicon has been implanted with nitrogen and phosphorus ions at MeV energies to fluences between 1016 and 1.6 × 1018 ions/cm2. Infrared transmission and reflection spectra in the range of 1.25 to 40 μm were measured for as-implanted samples and after various annealing treatments. Interference fringes were observed in the IR spectra which are produced by the interference of light which has been multiply reflected between the front surface and the buried layers. By detailed theoretical analyses of the interference fringe structure, we obtained refractive index profiles, which, under suitable interpretation, provide accurate measurements and several quantities of interest. These quantities are the range and straggling of the implanted ions, the depth of disordered layers, and the width of the order-disorder transition. Mechanisms for the refractive index changes which have been identified include amorphization of the implanted silicon, bulk compositional change in the buried layer, lo...

Specimens of synthetic monazite, CePO4, were rendered metamict by bombardment with 3 MeV Argon ions at fluences of 4 ions nm−2 or greater. Differential scanning calorimetry (DSC) was applied to the annealing of these specimens over a temperature range 550–720 K. The stored energy is shown to be 7.3±0.3 cal g1, independent of the fiuence from 4 to 10 ion nm−2. The activation energy of annealing of the damage is 2.7 ±0.3 eV and the temperature dependent rate constant is The application of DSC to the study of annealing of radiation damage in materials is discussed briefly. The saturation value of the stored energy with fiuence of 3 MeV Argon ions is compared to the approach to a saturation level observed in some glasses used to store radioactive wastes.