摘要:

A mirror polished (111)-oriented Ge single crystal substrate was implanted with 1.0 MeV Si+ions to a dose of ∼ 8.5 × 1017cm−2at room temperature. Rutherford backscattering spectrometry (RBS) together with ion channeling analysis with H+and He+beams have been used to study the Si distribution and radiation damage after implantation and subsequent vacuum annealing in the temperature range of 500–850°C. A non-RBS (resonance) measurement with an H+beam of specified energy is used to study the Si atoms distribution in Ge. The experiments reveal the existence of an extensive damage (possibly an amorphous layer) buried at a depth corresponding to the peak Si concentration. Annealing up to 850°C for 30 min does not result in the complete recovery of the lattice order. The annealing temperature dependence of the damage depth distributions in Ge has been evaluated using the multiple scattering model of Feldman and Rodgers. The composition of the alloy layer was measured by RBS followed by computer-simulated spectrum analyses. A tentative explantation of the results is presented.

ISSN:1042-0150    

DOI:10.1080/10420159908229004

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Calibrated Polyallyldiglycol Carbonate (PADC) detectors have been used to determine energy-loss and mean ranges of 13.04 MeV/u129Xeion in mica and Makrofol-KG using the nuclear track technique. The energy-loss rates (dE/dx) of the ion as a function of energy and depth of penetration in mica and Makrofol-KG have been derived from the respective energy-loss curves. Experimental data are compared with theoretical values obtained from four different sources. The significance and scope of the work is discussed.

ISSN:1042-0150    

DOI:10.1080/10420159908229005

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Thermo-responsive poly(N-isopropylacrylamide, NIPAAm) was grafted onto etchedtrack copolymer films with cylindrical pores of diameter 2.5 μm by means of post-polymerization at 60°C for 30 min after pre-irradiation of 30 kGy, using γ-rays from a60Co source to obtain a layer with a surface graft yield of 0.18 mg/cm2. The permeation of p-nitrophenol (PNP) through NIPAAm-grafted etched-track films, when measured at 30°C, was markedly depressed, to 7.12 × 10−5cm/min, compared with those measured below and above this temperature, e.g. 3.84 × 10−3cm/min at 29°C and 2.46 × 10−3cm/min at 31°C. This phenomenon can be explained by the existence of a theta-point (⊝) temperature, at which the hydrophilic interaction between the linear polymer of NIPAAm and water apparently disappears, resulting in permeation retardation of the water soluble PNP.

ISSN:1042-0150    

DOI:10.1080/10420159908229006

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The geometry of the etched tracks in polyethylene terephthalate has been analyzed during the chemical etching in 5 mole/l LiOH at 40°C after several etching times (90, 180, 270, 360 min) by the alpha-particle transmission method. The evolution of the etched track geometry was found to emerge from two separate opposite funnels via two interconnected cones combined with a cylindrical tube, up to two double-cone shapes combined with a central cylnder. The process of ion track etching was found to be rather erratic with an average track etching rate being about 30 times higher than bulk etching rate. The doublecone entrance shape of the pores points at slightly different structure of the near-surface area of the foil which might be due to the special thin foil production technology.

ISSN:1042-0150    

DOI:10.1080/10420159908229007

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The influence of swift heavy ion (SHI) irradiation on transport properties of epitaxial thin films of La0.75Ca0.25MnO3(LCMO) is studied. The films were irradiated with 90 MeV16O beams and 250 MeV107Ag beams at different fluence values. In the case of 90 MeV16O ions LCMO specimens were irradiated to 1011-1014ions/cm2and for 250 MeV107Ag ions with 1010–1013ions/cm2. A systematic variation in Curie temperature (Tc) or resistivity peak temperature (Tp) has been observed. It has been noted that for both types of ions theTpincreased for the specimen irradiated at 1011ions/cm2fluence. Further increase of fluence decreased theTpvalue and at higher fluence (1014ions/cm2for 90 MeV16O and 1013ions/cm2for 250 MeV107Ag ions) the specimens showed no metal-to-insulator transition even at low temperature down to 77K. They show completely semiconducting behavior with high resistance values. These results are discussed in terms of SHI irradiation-induced structural distrotion and strain on thin films.

ISSN:1042-0150    

DOI:10.1080/10420159908229008

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The hydrogen loss behavior in polymers under heavy ion irradiation is investigated for different electronic excitation energies. It is found that hydrogen loss under ion irradiation depends on the electronic energy deposition, and the type of bonds present in it. It is noticed that the hydrogen loss curve can be fitted with an equation contatining two exponential terms. The diminishing of hydrogen loss at higher fluences is discussed on the basis of overlapping of ion tracks.

ISSN:1042-0150    

DOI:10.1080/10420159908229009

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Indentation microhardness measurements have been carried out on large-grained polycrystals of alluminium produced by strain-anneal crystal growth. Anisotropy in hardness has been observed and it is described as planar anisotropy. The resistivity is also determined for samples thermally and non-thermally treated. It has also been found that the resistivity measurements can be used to obtain the longitudinal strain (ε) and to estimate the mechanical modulus.

ISSN:1042-0150    

DOI:10.1080/10420159908229010

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

ISSN:1042-0150    

DOI:10.1080/10420159908229003

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor