摘要:

A hexagonal ferromagnetic monopnictide, Mn1.07Cr0.11Sb, precipitates coherently along the (101)-planes of tetragonal Mn2−xCrxSb single crystals, acts as a nucleation site for the antiferromagmetic/ferrimagnetic transition of the bipnictide and introduces a quasifourfold anisotropy in the tetragonal plane.

ISSN:1042-0150    

DOI:10.1080/10420159708212945

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Polyvinyltoluene (PVT), a base polymer used for plastic scintillators, has been irradiated with 50–400 keV helium beam with fluency ranging between 109-1015ions/ (cm2s). Structural modifications induced by the ion bombardment are studiedin situby monitoring the desorbed species from the irradiated polymer films by a mass quadrupole spectrometer. The main desorbed chemical species are detected at the masses between 2 and 41 but even heavier masses such as monomers, are detected. The chemical yields of the emitted species depend on the molecular mass and, generally, are within 0.01–1 desorbed molecules per 100 eV of deposited energy.

ISSN:1042-0150    

DOI:10.1080/10420159708212946

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The three-dimensional distribution of 200 keV Hg+ions implanted into quartz has been reconstructed by means of the “Modified Tomographic Reconstruction” technique from a set of depth profiles for different implantation angles. We assume that the geometrical shape of the 3D distribution can be described by a simple function with only few adjustable parameters. The choice of a split Gaussian can reduce dramatically the number of necessary input profiles to only 3 or 4. In the case of 200 keV Hg implanted into quartz, the experimental profiles are wider than the theoretical predictions. This points perhaps to some anisotropic radiation enhanced mobility after the implantation which is preferentially into forward direction.

ISSN:1042-0150    

DOI:10.1080/10420159708212947

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Three mercury based oxycarbonates Hg1−xMxSr4Cu2(CO3)O6+xwith M = V, Mo and Cr have been irradiated at 300 K with 6 GeV Pb ions at fluences of 1011and 5 * 1011ions cm−2. They are the first layered copper superconductors whoseTcand diamagnetic volume fraction are drastically decreased by the irradiation induced defects. The experiments show that the irradiation effects are strongly dependent on the relative orientation of the ion beam with respect to the copper and carbonate planes. When the ion beam is oriented transverse to the layers, the tracks are continuous, with an average diameter of 70 Å, with a strongly disturbed core. When the ion path is roughly parallel to the layers, one observes dramatic damage of the matrix. This behavior is compared with that of the layered cuprates previously irradiated.

ISSN:1042-0150    

DOI:10.1080/10420159708212948

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Thin Ni films were prepared at room temperature by Ni metal vapor deposition on Si substrates and simultaneous irradiation by Ar ions with an energy of 2–20 keV. The reaction of Ni and Si during dynamic ion-beam mixing was studied. The fluences of the ion beam were 4.7 × 1017and 8.9 × 1017cm−2, and arrival rate ratios Ni/Ar were 9.7 and 5.1. Concentration profiles of Ni, Si, Ar, C, and O were analyzed with Auger electron spectroscopy; the surface morphology and the crystalline structure were investigated with a cross-sectional scanning electron microscope and X-ray diffractometry. The theoretical profiles were calculated with the dynamic Monte-Carlo simulation code T-DYN for comparison with the experimentally obtained profiles. It was possible to observe the ballistic mixing effects and also thermally activated formation of nickel silicide.

ISSN:1042-0150    

DOI:10.1080/10420159708212949

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

The interfacial structures of radiation hard and soft oxides grown on B- and P-doped single crystal silicon are examined using XPS before and after60Co radiation. Substantial differences of Si in the SiO2state (Binding Energy 103.4 eV), Si in the transitional state (B.E. 101.5eV) and Oxygen in the surplus oxygen state (B.E. 529.6eV) are observed in the Si-SiO2interface. The analysis of XPS spectra demonstrates that the influence of B is greater than that of P on the XPS spectra of Si-SiO2. The comparison of XPS spectra for four kinds of Si-SiO2interfaces indicates that, in addition to the oxidation process parameter, impurities in the Si substrate are important to control the features of SiO2. Finally, the experimental results are analyzed concerning the electron configuration of the atomic ground state and the differences between B and P in diffusive features.

ISSN:1042-0150    

DOI:10.1080/10420159708212950

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

In the present work, the effect of different doses of gamma rays ranging from 50 to 500 kGy on the transmission spectra and the tristimulus transmittance as well as the absorption coefficient in the range 400–700 nm of poly(vinyl chloride) (PVC) were studied by the optical transmission spectra. Variation in the group coordination in the near infrared region (700–3000 nm) were also studied. The data indicated that measurable and remarkable changes in the transmittance of the irradiated samples, as well as decrease in the tristimulus transmittance values, as compared to the unirradiated PVC sample were detected. Moreover, the irradiated samples acquire various colors depending on the radiation doses.

ISSN:1042-0150    

DOI:10.1080/10420159708212951

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor

摘要:

Pre-annealing influences the isothermal decomposition of γ-irradiated caesium bromate insofar as the damage entities facilitate the process in the initial period but decelerate the same in the subsequent stages. The fractional decomposition, α decreases with increasing pre-annealing time and proceeds through an initially accelerated gas evolution, and subsequent decay stage. The process follows the Prout-Tompkins relationship, showing that nucleation occurs in a chain branching manner.

ISSN:1042-0150    

DOI:10.1080/10420159708212952

出版商:Taylor & Francis Group    

年代:1997

数据来源: Taylor