Application of Band Parameters to Materials Design
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Availability of the two band parameters to materials design is reviewed. In order to express the chemical character between two different atoms in solid state, the concept of two band parameters for any bond between two different atoms is proposed on the basis of the bond orbital model and the empirical relation between observed band gap and pseudopotential radii of Zunger. The two band parameters are called as the hybrid function (<I>H</I>) and gap reduction parameter (<I>S</I>), which substantially correspond to the energy difference between the bonding and anti-bonding levels and the band widening effect due to the formation of crystalline state. These parameters roughly correspond to ionic and covalent band gaps which are constructed by one gap model. By comparing with the definition of ionicity based on the ionic and covalent band gaps, it is found that the ionicity for any A–B bond can be estimated from the two band parameters. Extensive availability of the band parameters to materials design is suggested by exemplifying several successful results such as the construction of crystal structure maps for compounds, determination of site preference of third alloying elements in intermetallics and prediction of phase changes in pseudobinary nitride films in the energetic processes.
- Transactions of the Iron and Steel Institute of Japan
Transactions of the Iron and Steel Institute of Japan 38(9), 925-934, 1998-09-15
The Iron and Steel Institute of Japan