Extended Data Fig. 2: Glide of a dislocation network in niobium.
The same dislocation network is imaged in a–c at three different times, using the diffraction vector g1 = (010). Two other diffraction vectors, g2 = (011) and \({g}_{3}=(0\bar{1}1)\), are used in d and e to determine Burgers vectors by extinction just after time t = 14 s as in c. The network is made of two interacting screw dislocation families with Burgers vectors \({{\bf{b}}}_{1}=1/2[\bar{1}1\bar{1}]\) and \({{\bf{b}}}_{2}=1/2[111]\), forming horizontal junctions with Burgers vector \({{\bf{b}}}_{JR}=[010]\) through the reaction \(1/2[\bar{1}1\bar{1}]+1/2[111]=[010]\). This network glides in the average plane \({P}_{12}=(10\bar{1})\) containing the three dislocation families, leading to the horizontal slip traces visible in all images, especially in e with diffraction vector g3 where dislocations 2 are out of contrast. The slip traces are clearly distinct for different emerging dislocations 1 and 2, which shows that the network is not entirely contained in a single P12 plane. The image difference f between a and c highlights the motion of the fastest node of the network, leading to a velocity of about 15 nm/s.
