Figure 3
Zone axis oriented selected-area electron diffraction pattern recorded from a thin-foil sample of aluminium alloy AlSi1MgMn in a JEOL JEM-F200 at 200 kV. The uncalibrated diffraction pattern was analyzed with the line and angle tools of ImageJ (Schneider et al., 2012) for determining the lengths of the three shortest reciprocal-lattice vectors A, B and C and the angles between them. For determining the distances of the reflections from the pattern center, lines were first drawn between the opposite reflections hkl and and the measured lengths were then divided by two. For the pattern shown here the thereby determined distances from the center are 209 pixels (A), 210 pixels (B) and 297 pixels (C), which yields the ratios
rB/rA = 1.0 and
rC/rA = 1.42. The measured angles are ∠A–B = 89.3° and ∠A–C = 45.3°. |