Crystallographic anisotropy

The first term in expression (1) describes the exchange energy, the second and the third terms give the crystallographic anisotropy energy. 

Marked examples of crystallographic anisotropy in adsorption are found in adsorption of nitrogen on W and Fe. The strong structural dependence is clear, and in the case of N dissociation on W and Mo, the morphology effect is much bigger than the difference between the two metals as stated earlier. The variation for Fe is significant in relation to ammonia synthesis since that metal is the material of choice (when in a promoted state) for industrial... 

Figure 2. Effect of piezoelectric anisotropy on the single-crystal orientational behavior. Left inset embodies the polar response of the normalized piezoelectric behavior for different anisotropy factors. Note that the optimal orientation changes as the degree of anisotropy increases. Left inset shows the optimal orientation of each single-crystal, as a function of crystallographic anisotropy. Note that contrary to what it is intuitively expected, in the limit of high anisotropy, A 2/3, the crystallographic orientation at which highest piezoelectric strains will occur will asymptotically align with the direction of the applied field. Furthermore, the optimal orientation for materials with weak anisotropy will asymptotically converge to 0=54.16°.

Dillamore, I.L., Roberts, W.T., Wilson, D.V. The Mechanical Properties of Stainless Steel with Particular Reference to Crystallographic Anisotropy, vol. 117, pp. 37-49. Iron and Steel Institute (1969)... 

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