Bin Feng

Grain boundary segregation is a critical issue in materials science because it determines the properties of individual grain boundaries and thus governs the macroscopic properties of materials. Recent progress in electron microscopy has greatly improved our understanding of grain boundary segregation phenomena down to atomistic dimensions, but solute segregation is still extremely challenging to experimentally identify at the atomic scale. Here, we report direct observations of atomic-scale yttr

Nanostructuring and second phase incorporation are considered to be promising ways of enhancing the thermoelectric performance of bulk materials. Here, a design principle is proposed which combines these two methods for improving the thermoelectric performance of p-type CoSb3 by fabricating a CoSb3/graphene (CoSb3/G) nanocomposite, where a second phase, graphene, is introduced in the nanostructured CoSb3 matrix via an in situ one-pot solvothermal route. In addition, CoSb3/G bulk materials were p

Material performance is significantly governed by grain boundaries (GBs), a typical crystal defects inside, which often exhibit unique properties due to the structural and chemical inhomogeneity. Here, it is reported direct atomic scale evidence that oxygen vacancies formed in the GBs can modify the local surface oxygen dynamics in CeO2, a key material for fuel cells. The atomic structures and oxygen vacancy concentrations in individual GBs are obtained by electron microscopy and theoretical cal

Crystalline interfaces in materials often govern the macroscopic functional properties owing to their complex structure and chemical inhomogeneity. For ionic crystals, however, such understanding has been precluded by the debatable local anion distribution across crystal interfaces. In this study, using yttria-stabilized zirconia as a model material, the oxygen vacancy distribution across individual grain boundaries was directly quantified by atomic-resolution scanning transmission electron micr

This paper presents a new optimization method for dynamic design of planar linkage with clearances at joints. The general consideration is to optimize the mass distribution of links to reduce the change of joint forces. The mass, the center position of mass and the moment of inertia the moving links are taken as the optimizing variables. The objective functions are taken as the changes of the amplitude and direction of the joint forces and they are minimized. The optimized result shows that the

In oxide materials, the presence of dislocations often strongly affects the properties of thin film and multilayer devices. Although it was reported that ionic conduction can be enhanced by introducing dislocations in ionic conductors, the underlying mechanism of such enhancement remains unclear. Here we analyzed the ionic conduction enhancement in an yttria-stabilized zirconia (YSZ) single edge dislocation from a structural point of view, using atomic resolution scanning transmission electron m

The atomic structure of a Σ3 [110]/(111) grain boundary in CeO2 was studied by scanning transmission electron microscopy, electron energy loss spectroscopy, and the first-principles calculations. It was revealed that this grain boundary does not promote the formation of oxygen vacancies and keeps oxygen stoichiometry, which is different from that of Σ5 CeO2 grain boundary studied previously [H. Hojo, T. Mizoguchi, H. Ohta, S. D. Findlay, N. Shibata, T. Yamamoto, and Y. Ikuhara, Nano Lett. 10, 46