Effects of Co/Sm Composition on the Ordered Phase Formation in Sm-Co Thin Films Grown on Cu(111) Single-Crystal Underlayers
Sm-Co thin films were prepared on Cu(111) single-crystal underlayers by changing the Sm composition from 12 to 35 at.% and the effects of Co/Sm composition on the ordered phase formation were investigated. The epitaxial SmCo5 thin films were obtained for all samples. The SmCo5 epitaxial layer grown on Cu underlayer has two different types of domains whose orientations are rotated around film normal by 30 degrees to each other. Cu atoms substitute a part of the Co sites in the SmCo5 structure, and an alloy compound of Sm(Co,Cu) 5 phase was formed for all samples. The Sm(Co,Cu)5 phase was more Cu enriched with increasing the Sm composition. The Cu atom diffusion into Sm-Co layer plays an important role in assisting the formation of Sm(Co,Cu)5 ordered phase.
Formation of Sm(Co1–xNix)5 epitaxial thin films on Cu(111) underlayers
Sm17(Co1-xNix)83 (at. %, x = 0, 0.2, 0.8, 1) alloy thin films are prepared on Cu(111) underlayers hetero-epitaxially grown on MgO(111) substrates by molecular beam epitaxy. The effects of substrate temperature and Ni/Co composition on the growth behavior and the detailed resulting film structure are investigated. Formation of RT5 ordered phase is enhanced with increasing the substrate temperature and the Ni composition. The long-range order degrees of Sm17Co83, Sm17(Co0.8Ni0.2)83, Sm17(Co0.2Ni0.8)83, and Sm17Ni83 films deposited at 500 °C are estimated to be 0.77, 0.82, 0.89, and 0.97, respectively. The Sm17(Co1-xNix)83 films with RT5 structure consist of two types of epitaxial (0001) variant whose orientations are rotated around the film normal by 30° each other. With increasing the Ni content ratio of x from 0 to 1, the volume ratio of two variants is varied from 53:47 to 94:6. The nucleation of only one-type variant with a smaller lattice mismatch with respect to Cu underlayer is promoted with increasing the Ni content ratio.
SR topography of plastically deformed Fe-Si bicrystals - observation in situ and post mortem
SR reflection topography was applied to study the interaction of slip dislocations with the grain boundaries in Fe-4at%Si bicrystals deformed by compression. Three experimental settings with either a white or monochromatic beam were used and the corresponding orientation contrast analysed. Dislocation transmission through the grain boundary was observed in bicrystals with favourable geometry of the slip systems.