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Techniques like electron backscattered diffraction (EBSD) and angle-resolved electron Rutherford backscattering (ERBS) are sensitive to the lack of inversion symmetry in crystals and hence can determine the absolute crystal orientation. In this paper we demonstrate for the case of GaP that medium energy ion scattering (MEIS) can also be used to obtain the absolute crystal orientation. A comparison between the 2D-backscattering intensities as a function of the detection directions for electrons (as is measured in EBSD or ERBS) and protons (as is measured in MEIS) is made and discussed in terms of diffraction and classical subchanneling respectively. [ABSTRACT FROM AUTHOR]

Crystalline silicon surfaces are modified by deposition of aluminum thin film that is sintered at 500 °C for different period of times. This treatment originates pyramidal pits and nanoparticles structures on the silicon surface. As a result, the sheet resistance of silicon surface increases. The analysis of the treated surfaces by Rutherford backscattering (RBS) and the impedance electrochemical spectroscopy (IES) reveals that, in addition to these defects, the aluminum atoms diffuse inside the silicon substrate, also contribute to the increase of the sheet resistance due to the formation of a high resistivity layer. In addition, the reflectance spectra of these samples reveal that after this treatment the complex refractive index of silicon crystal close to surface change and its surface becomes rough, as confirmed by the scanning electron microscopy (SEM). Although the higher sheet resistance of these substrates, they are more prone to be dissolved by HF attack when immersed into etchant composed by HF and HNO3, i.e., the etching rate of these samples becomes larger than in the case of the untreated substrate. This behavior is linked to the amount of oxygen incorporated within the silicon bulk during the thermal treatment. [ABSTRACT FROM AUTHOR]

In our earlier report, where we have demonstrated ferromagnetic behavior at room temperature (RT) in TiO 2 thin films deposited through electron beam evaporation technique followed by annealing either in Ar or O 2 atmosphere [Mohanty et al., Journal of Magnetism and Magnetic Materials 355 (2014) 240–245], here we have studied the evolution of structure and magnetic properties after irradiating the TiO 2 thin films with 500 keV Ar 2+ ions. The pristine film while exhibits anatase phase, the films become amorphous after irradiating at fluence in the range 1 × 10 14 to 1 × 10 16 ions/cm 2 . Increasing the fluence up to 5 × 10 16 ions/cm 2 , amorphous to crystalline phase transformation occurs and the structure becomes brookite. Although anatase to rutile phase transformation is usually reported in literatures, anatase to brookite phase transformation is an unusual feature which we have reported here for the first time. Such anatase to brookite phase transformation is accompanied with grain growth without showing any change in film thickness evidenced from Rutherford’s Back Scattering (RBS) measurement. From scanning probe micrographs (SPM), roughness is found to be more in amorphous films than in the crystalline ones. Anatase to brookite phase transformation could be realized by considering the importance of intermediate amorphous phase. Because due to amorphous phase, heat deposited by energetic ions are localized as dissipation of heat is less and as a result, the localized region crystallizes in brookite phase followed by grain growth as observed in highest fluence. Further, we have demonstrated ferromagnetic behavior at RT in irradiated films similar to pristine one, irrespective of their phase and crystallinity. Origin for room temperature ferromagnetism (RTFM) is attributed to the presence of oxygen vacancies which is confirmed by carrying out XPS measurement. [ABSTRACT FROM AUTHOR]

Bismuth/Nickel thin films were deposited on borosilicate glass substrates using an electron beam evaporator equipped with thickness monitor. Thin film of Bi (10 nm) was deposited on top of pre-deposited Ni (10 nm) film at 0.6 and 1.8 Å/second deposition rates. The samples were then annealed at temperatures between 60 °C and 260 °C for 1 to 5 h under vacuum of ~ 1 × 10 − 6 mbar. Scanning electron microscopy was used to investigate surface morphology. Scanning electron microscopy images depicted islands at all temperatures including the as-deposited sample. High resolution transmission electron microscopy reveals highly crystalline film and nanowires with energy dispersive x-ray spectroscopy showing that the film and nanowires were formed by Bi and Ni elements with oxygen as impurity. Rutherford backscattering spectrometry revealed intermixing of layers at the interface. Furthermore, spontaneous formation of NiBi 3 and NiBi stoichiometry was observed attributed to reaction-diffusion mechanism during deposition. X-ray diffraction revealed structural transformation of the films from amorphous (as-deposited) to polycrystalline hexagonal β-NiBi crystal structure at 60 °C to 200 °C. X-ray diffraction pattern also revealed hexagonal crystal lattice with preferential growth orientation along the [1 0 1] plane with other supported planes [0 0 2], [1 0 2], [1 1 0] and [1 0 3]. The results pointed toward successful utilization of this approach to prepare templates for the synthesis of well controlled, vertically aligned and well distributed crystalline nanowires of Ni-Bi binary system more relevant to the industrial application. [ABSTRACT FROM AUTHOR]

We describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event. We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10 − 3 to 0.3–0.7; the upper limit corresponds to Coulomb logarithm of 20–2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics. [ABSTRACT FROM AUTHOR]

Interface between dc sputtered In 2 O 3 and stepwise flash evaporated CuInTe 2 films were studied by probing Si/In 2 O 3 /CuInTe 2 and Si/CuInTe 2 /In 2 O 3 structures with the help of glancing angle X-ray diffraction, Rutherford backscattering spectrometry and micro-Raman spectroscopy. The results showed that in Si/In 2 O 3 /CuInTe 2 structure, a ∼20 nm thick interface consisting of In, Cu and O had formed between In 2 O 3 and CuInTe 2 and was attributed to the diffusion of Cu from CuInTe 2 into In 2 O 3 film. On the other hand, in Si/CuInTe 2 /In 2 O 3 structure, homogeneity of the underlying CuInTe 2 film was found lost completely. An estimate of the masses of the constituent elements showed that the damage was caused by loss of Te from CuInTe 2 film during the growth of In 2 O 3 film on Si/CuInTe 2 . [ABSTRACT FROM AUTHOR]

We have developed multi-channel apparatus for electron-atom Compton scattering to study the momentum distribution of atoms in a molecule. It combines the features of both a spherical electron energy analyzer and a large-area position sensitive detector, thereby having an ability to cover almost completely the azimuthal angle range available for quasi-elastic electron Rutherford backscattering at an angle of 135°. Details and performance of the apparatus are reported, together with experimental results measured for Xe and CH4 at an incident electron energy of 2 keV. In particular, it is shownthat the instrumental sensitivity is remarkably high, which has increased the signal count rate by nearly three orders of magnitude compared to existing setups. This technical progress would be useful for advancing atomic momentum spectroscopy studies. [ABSTRACT FROM AUTHOR]

Abstract: In 2012, our institute had initiated a series of research activities aimed to measure the characteristic x-ray production cross-section, arising from interaction of accelerated particles with target atoms. This paper presents the data of x-ray production cross-sections under excitation of K-, L- and M-shells of target atoms in the range of mass from Mg to Bi by protons of the energies in the range of 1–1.3MeV. We used the approach based on calculation of x-ray production cross sections through the cross-section of Rutherford backscattering, which can be calculated with high accuracy from the Rutherford formula. Such approach reduces the measurement errors of x-ray cross-sections and thus improves the accuracy of the obtained data. It is further planned to expand the area of research to protons of other energies and heavy charged particles in the energy range of 0.5–1.7MeV/nucleon. [Copyright &y& Elsevier]

Abstract: This paper reports the effects of annealing on structural and optical properties of nanostructured multi-layer TiO2–Ge thin films. These films were characterized using different techniques such as X-ray diffraction, X-ray reflectivity, Rutherford backscattering (RBS), and Fourier Transform Infrared spectroscopy. Annealing was responsible for pronounced changes in structural and optical properties of these films, as associated with changes in their structures, stoichiometry and stress-state. Three sets of TiO2–Ge multi-layer films were deposited by electron beam evaporation and resistive heating with different Ge layer thickness (5, 10 and 15nm), and TiO2 layer thickness was fixed to 20nm. The films were annealed in air up to 500°C for 2h. RBS studies showed that the layer structure of TiO2–Ge multi-layer films had been formed. The absorption spectra and band gap energy showed a blue shift with decrease in Ge layer thickness. The absorption spectra of these films suggest quantum confinement that increases with annealing temperature before the complete oxidation of Ge. Apparently complete oxidation results in sudden or sharp rise in band gap energy that matches with that of TiO2. RBS study reveals that layered structure of TiO2–Ge multi-layer films is not destroyed by annealing, which may be due to non-wetting behavior of Ge and its oxide with TiO2. These results imply that nanostructured TiO2–Ge multi-layer thin films may be employed as heterojunctions (with tunable band gap energy) based on quantum confinement effects for use in photovoltaics. [Copyright &y& Elsevier]

In order to obtain high spin injection efficiency, a ferromagnet-semiconducor Schottky contact must be of high crystalline quality. This is particularly important in the case of ferromagnet-silicon interfaces, since these elements tend to mix and form silicides. In this study Co-Si (100) interfaces were prepared in three different ways: by evaporation at room temperature, low temperature (-60°C), and with Sb as surfactant, and their interface structures were analyzed by high-resolution RBS (HRBS). In all cases more or less strong in-diffusion of Co with subsequent silicide formation was observed. In order to prevent the mixing of Co and Si, ultra thin MgO tunnel barriers were introduced in-between them. In situ HRBS characterization confirms that the MgO films were very uniform and prevented the mixing of the Si substrate with deposited Co and Fe films effectively, even at 450°C. [ABSTRACT FROM AUTHOR]

This paper treats a problem of nonstoichiometry in TiO2-y thin films deposited by reactive sputtering at controlled sputtering rates. Ion beam techniques, Rutherford backscattering (RBS), and nuclear reaction analysis (NRA) along with X-ray photoelectron spectroscopy have been applied to determine a deviation from stoichiometry y in the bulk and at the surface of TiO2-y layers. The critical review of these experimental methods is given. Defect structure responsible for the electrical resistivity of rutile TiO2 is discussed. [ABSTRACT FROM AUTHOR]