Strongest Grain Size

The following approaches estimate the strongest grain size. One approach is to assume that the plastic deformation of a nanocrystal switches abruptly from the pileup of dislocations to the GB-relaxation mechanism at a grain size, d = [53], 

Another approach for the flow stress of an A-B aUoy suggests that the strongest grain size represents the emergence of GB diffusion that causes the HPR breakdown. For the A-B aUoy, the critical grain size is given by [21]  

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Table 28.1 Comparison of the measured and predicted strongest critical grain sizes for IHPR transition with / = 0.5, 0.668 and m = 1 otherwise as indicated...

Films of zinc oxide were characterized by the same procedures used for Zr02. The three strongest X-ray diffraction peaks were found to be at 36.3 , 31.8°, and 34.5°, and these corresponded to the (101), (100), and (002) reflections of zinc oxide. The measured grain sizes for a 0.3 pm thick zinc oxide film was 0.1 pm and approximately 0.3 pm for a film of 1 pm thickness. The resistivity of zinc oxide, in the dark, was 1 x 10 2 cm. 

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