摘要:

The variation in the resistivity of then-type silicon along the range of protons and α-particles with an energy of 6.3 MeV/nucleon has been studied experimentally over a wide interval of irradiation doses. The initial rate of removal of majority carriers as a function of the distance from the surface of a sample has been determined. The spatial distribution of radiation-induced defects, resulting from elastic collisions between the incident particles and the silicon atoms and the subsequent cascade multiplication, has been calculated by a computer simulation technique.

ISSN:0033-7579    

DOI:10.1080/00337578108210039

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Energy distributions of atoms and molecules sputtered with 6 keV Ne+, Ar+, Kr+and Xe+beams have been measured at various temperatures of a LiI target. It was found that two processes contribute simultaneously to the sputtering of LiI. These are: (a) the collision cascade mechanism leading to a flux of sputtered particles Φcoll(E) ∼E/(E+Eb)3, whereEbis the surface binding energy, and (b) thermal evaporation of beam-decomposed material with a Maxwellian flux Φth(E) ∼Eexp(-E/kT). The last mechanism has been studied in more detail by varying the target temperature, the projectile and the ion current density. A comparison of the obtained results with previous experimental data as well as with sputtering theories is presented.

ISSN:0033-7579    

DOI:10.1080/00337578108210040

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

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.

ISSN:0033-7579    

DOI:10.1080/00337578108210041

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The results of Monte Carlo computer code simulations of backscattering for normally incident, monoenergetic light, keV ions bombarding planar amorphous (or polycrystalline) targets were compared to all pertinent experimental data found by the authors in the literature. These comparisons address a great many combinations of target material, ion species, and incident ion energy. For all combinations of targets and ions studitd, the reflection coefficientsRand backscattered energy fractions γ were found to be approximately universal functions of the ion's incident reduced energy ε. Empirical closed form expressions forRand γ were derived and are found to be given byR=R0e−αεand γ = γ0e−βεwhereR0= 11.1 ± 0.8, α= 0.275 ± 0.030, γ0= 4.1 ± 0.6, and β = 0.295 ± 0.040, valid in the range of 1.5 ≤ ε ≤ 9. The agreement between simulation and experimental data is generally very good, especially at the higher energies.

ISSN:0033-7579    

DOI:10.1080/00337578108210042

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Gold doped with radioactive111In was irradiated with electrons, protons and Au ions. The trapping of defects at the In atoms during isochronal annealing in stage III was investigated using the perturbed γγ-angular correlation technique (PAC). Via their characteristic electric field gradients four defect configurations were observed. Together with the results of quenched gold specimens we show that the recovery around 250 K is effected by at least two defect types, a small defect cluster being mobile at 195 K and the monovacancy migrating at about 245 K. Additionally, the formation of a large vacancy cluster at the probe impurity is observed at the end of stage III. The occurrence of the different defects is strongly influenced by the mass of the irradiating particles. The results are compared with the information supplied by other experimental methods, especially by resistivity measurements.

ISSN:0033-7579    

DOI:10.1080/00337578108210043

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Calculations of sink strength and bias are presented for arrays of edge dislocations constituting low-angle grain boundaries or deviations from perfect coincidence misorientations in high-angle grain boundaries. It is shown that the sink strength of an array increases as the dislocation spacing decreases: this also causes a strong decline in the bias. If a given Burgers vector content is arranged as a finer array of dislocations of smaller Burgers vectors, the resulting sink strength is higher and the bias lower.

ISSN:0033-7579    

DOI:10.1080/00337578108210044

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

In this experiment a polycrystalline Ag surface was bombarded by 0.8–3.2 keV Na+ions. The angle between the incident beam and the surface was tixed at 45°. The energy spectra of scattered Na+ions and secondary electrons were simultaneously measured. A shift to the lower energies of the Na+→ Na “single” scattering peak as well as L2.3MM Na Auger electron emission were observed. These effects are discussed and correlated.

ISSN:0033-7579    

DOI:10.1080/00337578108210045

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The neutral fraction of an energetic ion, Φch0, under the channeling conditions is calculated by taking into account the electron capture- and loss-probabilities. The numerical calculations for the cases of the random and the channeling conditions of H+in Ni are performed, and compared with experiments.

ISSN:0033-7579    

DOI:10.1080/00337578108210046

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Profiles of the Rb-, Cs- and Fr-ions in Ar- and N2-gases have been calculated at energies 20–100 keV using the Monte-Carlo method and potentials calculated from the Dirac-Fock electron distributions for single atoms. Good agreement with the recent range measurements of Sidenius is found for mean ranges and relative widths. The molecular effect is found to increase the ranges by 2–6% and the widths by 2–12%. Our calculations based on the modified LSS-theory agree with the Monte-Carlo calculations.

ISSN:0033-7579    

DOI:10.1080/00337578108210047

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Void motion under effect of an arbitrary nonuniform field is considered under the assumptions of the microscopic diffusion theory. The diffusion motion of particles over an arbitrary curvilinear surface under effect of this field has been considered separately. A general formula for void movement velocity has been obtained with allowance for the distortions of the vacancy and adatom jump probabilities as they move from one lattice point to another under a non-uniform field. The results are applied to a determination of void movement velocity in a temperature or elastic stress gradient.

ISSN:0033-7579    

DOI:10.1080/00337578108210048

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor