jMol series: lattice/diffraction unknown 231

Link here to a generic reciprocal lattice tutor, or trainers specific to srilankite (ZrTi2O6) and baddeyelite (ZrO2).

The left model shows a cluster of atoms only a few unit-cells across. The field width of the initial 300 pixel wide view is about 29 Ångstroms (or 2.9 nanometers).

A "flat Ewald slice" (kinematic electron diffraction pattern) of the corresponding reciprocal lattice is on the right. Assume that the half-width of the initial view there corresponds to a Nyquist spatial frequency of g = 0.86 cycles per Ångstrom (or 8.6 cycles per nm). Hence a diffraction spot centered on the right edge would correspond to vertical lattice fringes of spacing or periodicity d = 1/g ~ 1.16 Å (or 0.116 nm).

Challenge: By reorienting the specimen with the microscope controls below the display, try: (i) determining the lattice parameters (a, b, c, &alpha, β γ) for this crystal in terms of its standard basis triplet, and/or (ii) capturing a <110> zone diffraction pattern & indexing the spots in it. How many such zones are there? Here are calculators that might come in handy for the left and right sides of the figure.

/---- direct lattice ----/ | \-- reciprocal lattice --\
main axis: ; 2nd axis: ; rotate

direct space: ; reciprocal space:

Note: Even if the lattice type of the cluster looks familiar, the actual lattice parameters may not be what you expect. If you think you can identify the phase involved, how do the observed lattice parameters compare to values in the literature?