[010] Oxygen Ordering at Grain Boundaries in MgB2
نویسندگان
چکیده
منابع مشابه
Layering transitions at grain boundaries
We review various simplified models that have been advanced to describe layering (complexion) transitions at grain boundaries in multicomponent solids. In particular, we first outline lattice-gas, off-lattice atomistic and thermodynamic models that have been employed to investigate phase-like behavior at segregated grain boundaries. The results of these investigations are summarized in the form...
متن کاملLiquid nucleation at superheated grain boundaries.
Grain boundaries with relatively low energies can be superheated above the melting temperature and eventually melt by heterogeneous nucleation of liquid droplets. We propose a thermodynamic model of this process based on the sharp-interface approximation with a disjoining potential. The distinct feature of the model is its ability to predict the shape and size of the critical nucleus by using a...
متن کاملSolid-state wetting transitions at grain boundaries
A previously developed model of the dependence of grain boundary (GB) segregation on GB character has been exercised to investigate solid-state wetting transitions at GBs, and their anisotropy. In the case of binary systems displaying a solid-state miscibility gap, it is shown that the wetting transition temperature for precipitates at a GB is anisotropic, and is inversely related to GB energy....
متن کاملOxygen Vacancies at Grain Boundaries in Doubly-Doped Ceria Determined using EELS
In oxygen conducting ceramics such as cerium-based oxides, O 2diffusion occurs via vacancy hopping. The vacancy concentration can be modulated through doping with aliovalent cations such as Gd 3+ or Pr 3+ . Sluggish ionic conductivity in these electrolytes has been attributed to various defects which increase the activation energy for anion migration. The association of mobile oxygen vacancies ...
متن کاملAtomic structures and oxygen dynamics of CeO2 grain boundaries
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 ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Microscopy and Microanalysis
سال: 2002
ISSN: 1431-9276,1435-8115
DOI: 10.1017/s1431927602103527