Convergent-beam electron diffraction of CaZr4O9, a complex zirconia alloy phase

The point-group and space-group symmetry of the controversial fluorite-based stoichiometric superlath phase of ø₁ (CaZr₄O₉: Z=16), considered to be a coherently-intergrown subphase of lime-stabilized zirconia, is examined. Using convergent-beam and selected-area electron diffraction, it is determined that the space group of ø₁ is C2/c, in apparent agreement with earlier studies utilizing other diffraction techniques.