Hematite on Magnetite - True Epitaxy
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EXAMP11

This illustrates a crystal nucleating on another, with the two continuing to grow together for a period of time.
Enter the hematite on magnetite example number 6, with the following changes: 1) for simplicity, use only the form {111} for magnetite; 2) for the hematite epitaxial crystal, select interpenetration, at a distance 0.85, instead of a contact relation; 3) use the central distance 0.36, instead of 0.1 for the {001} form of hematite.

After the crystal has generated, select Align Face/Vector from the Rotation menu and rotate the face (111) parallel to the screen, using alignment vector [11-2]. Then select Cartesian Axes and rotate 90 degrees on z. This gives a view down the epitaxial plane, showing the hematite to be partially buried in the magnetite.

Now select Sections/Growth Zones from the Input1 menu. Click on the Growth Zones radio button, and then on the Zone Settings button. In the Growth-Zone Settings dialog, click on the Linear button, and enter 20 in the number of zones box. At the bottom of the dialog, click on the Times button, which brings up the Start and End Times... dialog. Set the start and end times for crystal 2, the first epitaxial crystal to 0.8 and 1.15 respectively. Exit the dialogs and reset the display mode, if necessary, as for the previous examples.

The start time of 0.85 causes the hematite to start to grow just as the host magnetite reaches its center, simulating epitaxial nucleation. The two crystals grow together in the time interval 0.85 to 1.0 (host growth time), forming the small "root", and the epitaxial hematite grows alone in the interval 1.0 to 1.15.