104379.fig.0017a
(a)
104379.fig.0017b
(b)
104379.fig.0017c
(c)
Figure 17: (a) Energy gap versus temperature of a NbN sample for both main axes of the substrate. Solid lines are the fits according to BCS theory. Results on both main axes yield very similar values of . The error bar shown is representative for all data. (b) at 4.2 K and (c) ratios versus of several NbN films deposited with different parameters, yielding different transition temperatures (after [72]).