Abstract: The phase transformation sequences during thermal decomposition are investigated for Ni-rich melt-quenched body-centred cubic (bcc) and amorphous Ni-Zr alloys. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) are used to determine the structure of crystallization products occurring after heating the melt-spun ribbon samples to various degrees of the phase transformation process monitored by differential scanning calorimetry (DSC). A single DSC peak is observed for both the bcc and amorphous Ni(91)Zr(9) alloys and a two-step process is indicated by DSC for the amorphous Ni(90)Zr(10) alloy. In the bcc-Ni(91)Zr(9) alloy which is actually a Ni(Zr) solid solution phase, the phase transformation starts with the precipitation of Ni(5)Zr crystallites followed, after a sufficient depletion of the matrix in Zr, by the subsequent transformation of the bcc-Ni(Zr) lattice to face-centred cubic (fcc) Ni. In the amorphous alloy of the same composition, the final products are fcc-Ni and Ni(5)Zr but at intermediate stages of the phase transformation, bcc-Ni(Zr) crystallites also appear. In the a-Ni(90)Zr(10) alloy the first DSC peak corresponds to the formation of the bcc-Ni(Zr) phase which then decomposes (second DSC peak) to the equilibrium phases fcc-Ni and Ni(5)Zr. Thus, in addition to the previous observation of the formation of the metastable bcc-Ni(Zr) phase by rapid quenching from the melt, here we present evidence that this phase can form also after partial crystallization of metallic glasses of appropriate chemical compositions.

Abstract: Recent technological advances resulted in high-quality superconducting metallic nanofilms and nanowires. The physical properties of such nanostructures are governed by the size-quantization of the transverse electron spectrum. This has a substantial impact on the basic superconducting characteristics, e.g., the order parameter, the critical temperature and the critical magnetic field. In the present paper we give an overview of our theoretical results on this subject. Based on a numerical self-consistent solution of the Bogoliubov-de Gennes equations, we investigate how the superconducting properties are modified in the quantum-size regime.

Abstract: Recent developments in the field of TEM characterisation of Si device materials are discussed and illustrated by a few case studies of material in different stages of various kinds of processing. Important challenges are the ever decreasing defect densities and device feature sizes. Defect delineation techniques using large area inspection tools yielding accurate coordinates of the defects to be studied have therefore become an essential part of the TEM analysis procedure. The possibility to transfer these defect coordinates without loss of accuracy to tools for local TEM specimen preparation is also a conditio sine qua non for a successful analysis. Insitu TEM remains important as dynamic processes can be observed and analysed under well defined experimental conditions. As case studies illustrating new developments, results are presented on defects in as-grown Ct silicon, on in-situ studies in processed silicon, on problem sites in advanced integrated circuit structures and on assessment of localised strain fields in the nm size scale.

Abstract: Multishell tabular grains have a higher speed than pure AgBr tabular grains. Usually the shells differ in size and iodide content, but also the precipitation method for the iodide containing shells has an influence on the iodide incorporation. A TEM investigation was performed to determine the defect structure of multishell AgBr (111) tabular crystals containing a shell with a low iodide concentration and one with a high iodide concentration. The twins that induce tabular growth and stacking fault contrast in the region of the iodide shells have been observed, similar to previously studied AgBr/Ag(Br,I) coreshell crystals. Moreover in some of the crystals dislocations have been observed, sometimes even an entire network. The number of dislocations formed varies for the different methods of iodide addition. Also variations in average thickness between the different iodide addition methods have been observed. A higher number of dislocations and thicker crystals point towards a higher local concentration of iodide. These observations allow deciding which iodide incorporation method is most useful for a preferred dislocation pattern.

Abstract: Transmission electron microscopy has been applied to study Ti and Al/Ti contacts on GaN and AlGaN/GaN as a function of annealing temperature. This has lead to a profound understanding of the role of Al, both in the contact formation on n-GaN and on AlGaN/GaN. Al in the AlGaN decreases the N-extraction by Ti out of the nitride, because of the strong Al-N bond. Al in the metal bilayer also reduces the N-extraction by Ti due to a preferential alloy mixing.