$crystalmaker electron diffraction pattern example$

$crystalmaker electron diffraction pattern example$

The allowed diffractions from fcc structures should have h, k, l are all even or all odd (see page3560), so that we list the lowest order diffractions in the diffraction pattern below: Vii) Since there are not many candidates left, we can start to guess and test our guess. Therefore, we narrow down the list again: Vi) The, and zone axes are further ignored because their symmetries (see diffraction patterns for FCC) does not match that of the analyzing diffraction pattern in Figure 3090a.

$crystalmaker electron diffraction pattern example$

V) We know three directions above (,, and ) are the same, so that we need only consider the lowest index direction as a possible zone axis and can narrow down the list: Iv) List all the lowest order zone axes for fcc structure: Then, the lowest order zone axes will be our first try. Iii) We notice that the pattern in Figure 3090a is very likely a low-order zone axis as the density of spots is high.

$crystalmaker electron diffraction pattern example$

Otherwise, we can more generally index the pattern by skipping this step and performing the next step. Note that for other structures, we can also find the relevant standard diffraction patterns at link. Ii) The easiest way is to index it by referring to the Standard Indexed Diffraction Patterns for fcc Crystals on page3915.

$crystalmaker electron diffraction pattern example$

Measurements of the reciprocal lattice spacings and the angle between the basis vectors a' and b'.

$crystalmaker electron diffraction pattern example$

Crystalmaker electron diffraction pattern example