Search results for "LEM"

Analysis of thin high-k and silicide films by means of heavy ion time-of-flight forward-scattering spectrometry

2006

The use of forward scattered heavy incident ions in combination with a time-of-flight-energy telescope provides a powerful tool for the analysis of very thin (5–30 nm) films. This is because of greater stopping powers and better detector energy resolution for heavier ions than in conventional He-RBS. Because of the forward scattering angle, the sensitivity is greatly enhanced, thus reducing the ion beam induced desorption during the analysis of very thin films. The drawback of forward scattering angle is the limited mass separation for target elements. We demonstrate the performance of the technique with the analysis of 25 nm thick NiSi films and atomic layer deposited 6 nm thick HfxSiyOz f…

A comparative study on the compatibility of liquid lead–gold eutectic and liquid lead–bismuth eutectic with T91 and SS 316LN steels

2012

Abstract Liquid lead–gold eutectic (LGE) is considered as a potential target material for high power spallation sources. In the present work, the corrosion effects of LGE on T91 and SS 316LN steels have been investigated in comparison with that of liquid lead–bismuth eutectic (LBE) under the same testing conditions. Two tests were conducted at 400 °C for 1800 h and at 450 °C for 1300 h, in which specimens of the two steels were exposed to 1 m/s flowing LGE and LBE. Surface inspections showed that the specimens underwent a mixed corrosion mode of dissolution and oxidation. The results obtained from the SS 316LN specimens are very interesting. Firstly, EDX (electron energy dispersion X-ray sp…

Thermal annealing of radiation damage produced by swift 132Xe ions in MgO single crystals

2020

Abstract The annealing kinetics of the electron-type F+ and F color centers in highly pure MgO single crystals irradiated by 0.23-GeV 132Xe ions with fluences covering three orders of magnitude (Φ = 5 × 1011 –3.3 × 1014 ions/cm2) are studied experimentally via dependence of the optical absorption on preheating temperature. The annealing data are analyzed in terms of the diffusion-controlled bimolecular reactions between F-type centers and complementary interstitial oxygen ions. The behavior of the main kinetic parameters – the migration energies and pre-exponential factors – for different irradiation fluences is discussed and compared with that for other wide-gap binary materials from previ…

Lattice sites of diffused gold and platinum in epitaxial ZnSe layers

2000

Abstract The lattice location of diffused gold and platinum in zinc selenide (ZnSe) epitaxial layers was studied using the Rutherford backscattering (RBS) channeling technique. Thin Au and Pt films were evaporated onto ZnSe samples. The Au/ZnSe samples were annealed at 525°C and the residual Au film was removed by etching. Channeling angular scan measurements showed that about 30% of Au atoms were close to substitutional site (displaced about 0.2 A). In the case of the Pt/ZnSe samples the annealing temperatures ranged from 600°C to 800°C. The Pt minimum yields along 〈1 0 0〉 direction were close to the random value, varying from 80% to 90%. The measured Pt angular scans along 〈1 0 0〉 and 〈1 …

On the solution of a parabolic PDE involving a gas flow through a semi-infinite porous medium

2021

Abstract Taking as start point the parabolic partial differential equation with the respective initial and boundary conditions, the present research focuses onto the flow of a sample of waste-water derived from a standard/conventional dyeing process. In terms of a highly prioritized concern, meaning environment decontamination and protection, in order to remove the dyes from the waste waters, photocatalyses like ZnO or TiO2 nanoparticles were formulated, due to their high surface energy which makes them extremely reactive and attractive. According to the basics of ideal fluid, the key point is the gas flow through an ideal porous pipe consisting of nanoparticles bound one to each other, for…

Non-Linearity Extremum in Niobium Doped Potassium Tantalate

1997

We report non-linear dielectric measurements in the KTaO 3 :Nb system (x Nb ≤ 0.05). The non-linear susceptibility diverges at low temperatures and reaches maximum values in the intermediate range (0.0075 ≤ x Nb ≤ 0.02). To account for this extremum non linearity, we propose a model of temperature dependent clusters which fits with a number of experimental reports. We also suggest that this model may be applied to the related compounds SrTiO 3 :Ca and KTaO 3 :Na.

Study of the thermochromic phase transition in CuMo1−xWxO4 solid solutions at the W L3-edge by resonant X-ray emission spectroscopy

2021

Abstract Polycrystalline CuMo 1 − x W x O 4 solid solutions were studied by resonant X-ray emission spectroscopy (RXES) at the W L 3 -edge to follow a variation of the tungsten local atomic and electronic structures across thermochromic phase transition as a function of sample composition and temperature. The experimental results were interpreted using ab initio calculations. The crystal-field splitting parameter Δ for the 5d(W)-states was obtained from the analysis of the RXES plane and was used to evaluate the coordination of tungsten atoms. Temperature-dependent RXES measurements were successfully employed to determine the hysteretic behaviour of the structural phase transition between t…

2021

Atomic layer deposition (ALD) technology has unlocked new ways of manipulating the growth of inorganic materials. The fine control at the atomic level allowed by ALD technology creates the perfect conditions for the inclusion of new cationic or anionic elements of the already-known materials. Consequently, novel material characteristics may arise with new functions for applications. This is especially relevant for inorganic luminescent materials where slight changes in the vicinity of the luminescent centers may originate new emission properties. Here, we studied the luminescent properties of CaS:Eu by introducing europium with oxygen ions by ALD, resulting in a novel CaS:EuO thin film. We …

Dynamics of quantum discord of two coupled spin-1/2’s subjected to time-dependent magnetic fields

2019

Abstract We describe the dynamics of quantum discord of two interacting spin-1/2’s subjected to controllable time-dependent magnetic fields. The exact time evolution of discord is given for various input mixed states consisting of classical mixtures of two Bell states. The quantum discord manifests a complex oscillatory behaviour in time and is compared with that of quantum entanglement, measured by concurrence. The interplay of the action of the time-dependent magnetic fields and the spin-coupling mechanism in the occurrence and evolution of quantum correlations is examined in detail.

Simulation and optimization of the implantation of holmium atoms into metallic magnetic microcalorimeters for neutrino mass determination experiments

2017

Abstract Several novel experiments designed to investigate the electron neutrino mass in the sub-eV region are based on the calorimetric measurement of the 163Ho electron capture spectrum. For this the 163Ho source, with a required activity of the order of 1 to 100 Bq , needs to be enclosed in the detector, having a volume smaller than 10 − 3 mm 3 . Ion implantation is presently considered to be the most reliable method to enclose this source in the detector homogeneously distributed in a well defined volume. We have investigated the distribution of implanted holmium ions in different target materials and for different implantation energies by means of Monte Carlo simulations based on the S…