Characterization of room-temperature plastic deformation of ß-Si3N4 by atomic force microscopy and transmission electron microscopy

Dislocation microstructures induced by room-temperature microhardness tests have been investigated in silicon nitride. Surface analysis of the residual indent by atomic force microscopy reveals intragranular slip bands and demonstrates that room-temperature plastic deformation involves dislocation motion as well as cross-slip events. Cross-slip events have been found to occur between {1010} prismatic planes. Transmission electron microscopy shows that dislocations have a Burgers vector b = [0001] and are located along the screw direction. Based on these observations, specific dislocation core configurations are discussed.     

Study of γ/γ′ interfacial width in a nickel-based superalloy by scanning transmission electron microscopy

The γ/γ′ interfaces are thought to play an important role in determining the mechanical properties in single-crystal nickel-based superalloys. In this article, interfacial width in DD6, one second-generation single-crystal superalloy containing 2 wt% Re, has been studied by means of scanning transmission electron microscopy. From an atomic resolution high angle annular dark field image, both compositional interfaces and order–disorder interfaces are studied, and it is first found that the interfacial width of chemical composition is same with that between the ordered and disordered phases.     

Study of incommensurate modulation in V-doped La2Cu1- x (VO) x O4 + δ by transmission electron microscopy

Structural variations in a hole-rich grain of V-doped La₂Cu_{1? x} (VO) _x O_{4+ δ} (x?=?0.045, δ?=?0.011) superconducting compound have been studied by electron diffraction and high-resolution transmission electron microscopy. Two types of one-dimensional (1-D) incommensurate modulation were observed one after the other when the specimen was exposed to electron beam irradiation. The features of these two modulated structures have been studied and are discussed.