Search

The use of genetically modified organisms - their release into the environment, import, and utilisation as food/feed or food/feed ingredients - is regulated in the European Union (EU). For placing onto the market, current legislations require a comprehensive and science-based risk assessment. This risk assessment (RA) is performed by applicants and then evaluated by national authorities in close cooperation with the European Food Safety Authority (EFSA). The EFSA Panel on Genetically Modified Organisms (GMO) has published a comprehensive set of guidance documents for applicants and risk assessors for the RA of GM plants (GMP), their products for food and/or feed use, and their cultivation. In those documents, the strategy and the criteria to conduct the assessment are explained, as well as the scientific data to be provided by the applicant. The assessment starts with the molecular characterisation of the GMP. If the GMP or products derived from it are to be consumed, the evaluation of its composition, potential toxicity and/or allergenicity, and nutritional value constitute further cornerstones of the process. The environmental risk assessment (ERA) considers biotic and abiotic interactions and the impacts of the management of the GM plant when it is intended for cultivation. In the case of GM trees special emphasis would be placed on assessing their characteristic features such as their longevity, ability to disperse and their ecological significance in a range of environments. The outcome of the assessment is reflected in a published opinion from the EFSA GMO panel that indicates whether the GMP and its products raise any safety issues. This scientific opinion constitutes one of the elements taken into account by the different European regulatory authorities prior to a decision regarding authorisation to commercialise the product.

The controlled formation of silicide materials is an ongoing challenge to facilitate the electrical contact of Si-based transistors. Due to the ongoing miniaturisation of the transistor, the silicide is trending to ever-thinner thickness's. The corresponding increase in surface-to-volume ratio emphasises the importance of low-energetic interfaces. Intriguingly, the thickness reduction of nickel silicides results in an abrupt change in phase sequence. This paper investigates the sequence of the silicides phases and their preferential orientation with respect to the Si(001) substrate, for both “thin” (i.e., 9 nm) and “ultra-thin” (i.e., 3 nm) Ni films. Furthermore, as the addition of ternary elements is often considered in order to tailor the silicides' properties, additives of Al, Co, and Pt are also included in this study. Our results show that the first silicide formed is epitaxial θ-Ni2Si, regardless of initial thickness or alloyed composition. The transformations towards subsequent silicides are changed through the additive elements, which can be understood through solubility arguments and classical nucleation theory. The crystalline alignment of the formed silicides with the substrate significantly differs through alloying. The observed textures of sequential silicides could be linked through texture inheritance. Our study illustrates the nucleation of a new phase drive to reduce the interfacial energy at the silicide-substrate interface as well as at the interface with the silicide which is being consumed for these sub-10 nm thin films. [ABSTRACT FROM AUTHOR]

Several in situ techniques are used to study the formation and degradation of NiSi films, when different alloying metals with a high melting point, like W, Ti and Ta, are added to pure Ni films in different concentrations at different temperatures. The results demonstrate the improvement in the morphological stability of the films on addition of such metals, which further increases the activation energy for NiSi formation.

Author(s): C. Detavernier (corresponding author) [1, 2]; A. S. Ãzcan [3]; J. Jordan-Sweet [1]; E. A. Stach [4]; J. Tersoff [1]; F. M. Ross [1]; C. Lavoie (corresponding author) [1] [...]

While the process of metal induced crystallization (MIC) is widely used in the fabrication of thin film electronic devices, its application to the field of thermoelectrics is fairly new. Especially, its implementation in the field of the classic thermoelectric material SiGe could lead to a low cost approach by combining the benefits of low thermal budget, self-doping, and thin film and sputter deposition compatibility. In this work, samples consisting of SiGe/Al multilayers deposited on aluminum oxide based substrates have been prepared. Special emphasis was put on the ratio of Al to SiGe and the resulting changes in transport properties during annealing. On one hand, a certain amount of Al is needed to ensure a complete MIC process for the SiGe, but on the other hand, an excess of Al results in a metallic system with low thermoelectric efficiency. In-situ characterization during annealing of the samples was carried out via x-ray diffraction, electrical resistivity, and Seebeck measurements. [ABSTRACT FROM AUTHOR]

We studied the solid-phase reaction between a thin Ni film and a single crystal Ge(001) or Ge(111) substrate during a ramp anneal. The phase formation sequence was determined using in situ X-ray diffraction and in situ Rutherford backscattering spectrometry (RBS), while the nature and the texture of the phases were studied using X-ray pole figures and transmission electron microscopy. The phase sequence is characterized by the formation of a single transient phase before NiGe forms as the final and stable phase. X-ray pole figures were used to unambiguously identify the transient phase as the ϵ-phase, a non-stoichiometric Ni-rich germanide with a hexagonal crystal structure that can exist for Ge concentrations between 34% and 48% and which forms with a different epitaxial texture on both substrate orientations. The complementary information gained from both RBS and X-ray pole figure measurements revealed a simultaneous growth of both the ϵ-phase and NiGe over a small temperature window on both substrate orientations. [ABSTRACT FROM AUTHOR]