Figure 10
The plot of 
versus d
2 (P, T) for neutron diffraction data on Ni. Similar to the X-ray observations (Fig. 6), the raw data below 873 K (open black symbols) are highly scattered, and the data corrected by DER2 = (E
hkl
/E
200)2 (the solid blue symbols) are lined up nicely in a linear fashion. Also shown in the plots are corrected data using DER2 = (E
hkl
/E
111)2, which would provide lower bounds for strains and upper bounds for grain sizes. AtT ≥ 873 K, the slopes become negative for both the raw and corrected data at T ≥ 873 K (the bottom panel), indicating that the grain size information can no longer be extracted from Eq.2. We interpret this phenomenon as an indication of the growth of nanocrystals approaching or into the micrometer region