Pure magnesium and three binary Mg–Y alloys (0.23, 0.84 and 2.71wt%Y) have been deformed in plane strain compression under conditions where dynamic recrystallization (DRX) is observed. The development of crystallographic texture during deformation has been determined for both the parent and DRX grains. In all but the highest Y alloy, the texture of the DRX grains was found to follow that of the parent grains closely in all alloys, implying that the DRX texture is dominated by the deformation conditions, rather than preferred nucleation or growth. In the highest Y alloy, the DRX texture is randomized, which also suggests that preferred nucleation or growth is not responsible for texture formation in this alloy. A transition in macrotexture development was observed in going from pure Mg deformed at 250°C, to Mg–2.71wt%Y deformed at 450°C. This can be attributed to activation of additional slip modes, and a concomitant decrease in the contribution of twinning to deformation.

A solvothermal method has been used to produce nanoparticles of cubic/tetragonal yttria‐stabilized zirconia (YSZ) with uniform particle size, homogenous composition, and high crystallinity. The effects of reaction time, reactant concentration, processing temperature, and solvent composition on prime particle size and YSZ phase proportion have been investigated. The effect of solvent, a mixture of ethanol/2‐propanol, on crystallite size and agglomerate size was studied and discussed according to Derjaguin‐Landau‐Verwey‐Overbeek (DLVO) theory and surface chemistry. The prime particle diameter was 2–4 nm and secondary particle size was 140–180 nm. After compaction and sintering at 1000°C, YSZ with a grain size of approximately 50 nm in diameter was obtained with a typical relative density of 94%.

Yttria stablised zirconia (YSZ) and tetragonal ZrO2 (t-ZrO2) nanoparticles were synthesised by a solvothermal method using ethanol and isopropanol as solvents. Monodispersed YSZ and t-ZrO2 nanoparticles were produced in ethanol. Uniform spherical aggregates of YSZ nanoparticles were obtained in the isopropanol solution. It was found that the average crystallite size was independent of starting material, solvent and product morphology. The solvent had a major effect on the morphology of the aggregates/agglomerates formed from the initial nanocrystallites. The solvothermal YSZ nanopowder was compared with YSZ nanopowder produced by conventional precipitation-calcination using simultaneous differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The particle size distribution of the agglomerates/aggregates was investigated by light diffraction.

The precipitation sequence in two commercial magnesium alloys, WE43 and WE54, are described. The technique of in-situ thin foil microanalysis has been used to determine the composition of the transition phases formed in WE54. A loss of ductility of both alloys, initially in the T6 condition (solution treated, quenched and aged for 16h at 250 degrees C), during extended exposure to temperatures as low as 100 degrees C is shown to be associated with the precipitation of G.P. zones and the intermediate phase beta " within the microstructure developed by the initial T6 treatment.

Presents a study of the electrical properties of deep states in silicon containing oxidation-induced stacking faults and dislocations. In general the electrical activity of stacking faults is associated with the Frank partial dislocation bounding it rather than the extra plane of the fault itself. In addition, the deep states associated with the partials of very clean stacking faults are rather ineffective as either generation or recombination centres. The authors have studied the effect of annealing oxidation-induced stacking faults in nitrogen and of decorating them with silver. After low-level decoration the defect states increase in concentration and the electron binding energy changes, tending to move the states towards the middle of the gap (hence increasing their effectiveness as generation centres). This level of decoration is not detectable with present-day TEM techniques. However, if the level of decoration is increased further, precipitates can be observed (using TEM) but the concentration of deep states decreases as does their electron binding energy. During this precipitative phase the intensity of the photoluminescence D lines is also seen to decrease substantially. These factors have a very considerable significance in relation to the imaging of extended defects using techniques which rely on recombination-generation effects and imply that the visibility of such defects is crucially dependent on the level of decoration.

Oxygen-induced stacking faults have been generated at a concentration of about 107 cm−2 in n-type silicon. The photoluminescence, electron capture and electron emission from clean stacking faults and from faults decorated with gold and platinum have been investigated. In contrast to previously published work on extended defects in plastically deformed silicon we observe a simple photoluminescence spectrum dominated by the D1 line with a weak D2 emission; other D lines are absent. Using deep level transient spectroscopy we observed electron traps with an activation energy of 415 meV which vary linearly in concentration with the stacking fault density. This activation energy increases when either gold or platinum is diffused into the sample, tending to move the state towards midgap where it acts as a powerful generation centre. The capture properties of the stacking-fault-related deep state are also modified by decoration. The behaviour is almost point defect like for “clean” stacking faults but capture tends towards the previously reported logarithmic behaviour in the decorated case.