[en] The results of microstructural characterization of rapidly-solidified (RS) foils irradiated in the High Flux Isotope Reactor (HFIR) to 14 dpa/750 appm He at 773 K and 873 K are reported. RS foils with nominal Ti and C concentration of 1, 3 and 5 times the amount contained in prime candidate (PCA) stainless steels (0.32 Ti, 0.046 C) were prepared and three thermomechanical treatment were employed to obtain variations in the pre-irradiation microstructures. Quantitative electron microscopy results for void swelling, dislocation structure, radiation-induced phase transitions and segregation of defects/He to interphase boundaries are discussed. Higher swelling was found at 773 K compared to 873 K and in annealed materials, consistent with a model for swelling suppression based on thermal and recoil re-solution precipitation effects. Voids were not found at particle/matrix interfaces. Under the conditions of this experiment, RS processing and increased Ti and C did not significantly alter the swelling behavior

[en] The dislocation densities, surface morphology, and strain of Ga/sub 1-//sub x/In/sub x/As/GaAs epitaxial interfaces as a function of indium composition and layer thickness have been investigated by transmission electron microscopy, medium energy ion blocking, and double-crystal x-ray diffractometry. The electron microscopy shows that in the thinnest dislocated films (90 and 160 nm, x = 0.07) 60⁰ α dislocations form first in one <110> direction at the interface. Surprisingly, however, an asymmetry in residual layer strain is not detected in these samples, suggesting that the dislocations have the same Burgers vector or are evenly distributed between two Burgers vectors. Orthogonal arrays of dislocations are observed in films thicker than 300 nm (60⁰ and edge-type, x = 0.07). In this case, dislocation densities in each <110> direction are equal to within experimental error while an asymmetry in in-plane strain is measured (18% and 30% for x = 0.07, 300, and 580 nm thick, respectively). An unequal distribution of Burgers vectors of 60⁰ or edge-type dislocations is considered responsible for the strain asymmetry in these thicker samples