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When BaTiO3 is cooled below the Curie point (120°C), the cubic structure changes slightly, so that $Ti^{4+}$ shifts by 0.006nm away from its position at the center of the cube. I don't know why this happens, but it makes the material piezoelectric.

I suppose that CaTiO3 has a very similar structure, but it is not piezoelectric. Does anybody know why this is so?

Samuel
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1 Answers1

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One approximate answer to this problem is the following:

The $Ca^{2+}$ is smaller than the $Ba^{2+}$ ion. For this reason, even below the Curie point, there is enough space to keep the cubic structure.

I suppose that this is true. But it still doesn't explain why it makes a difference if we are below or above the Curie point (120°C) for BaTiO3.

Samuel
  • 140