Fig. 8: Photographs of Sample 1 mounted in the capacitive dilatometer.

The three panels show the NbxBi2Se3 sample mounted along the three measured directions within the Bi2Se3 basal plane. The dotted lines mark the 90° direction, which corresponds to one of the crystalline a* directions (parallel to the mirror plane). The lower row of images illustrates the corresponding crystalline orientations. The red lines mark the crystalline a directions (perpendicular to the mirror plane) as determined by Laue X-ray diffraction. The blue lines mark the measured directions.