Journal of the American Ceramic Society, Vol.83, No.8, 2097-2099, 2000
Surface relief induced by martensitic transformation in phosphorus-bearing dicalcium silicate
Crystals of (Ca(1.955)square(0.045))(Si0.91P0.09)O-4, where square denotes a vacancy, have been prepared and examined by XRD, optical microscopy, SEM, and AFM. At 20 degrees C, the crystals are composed of 38% alpha(L)' and 62% beta phases, Upon cooling to -185 degrees C, the alpha(L)'- to beta-phase transformation occurs, which increases the P-phase composition to 72%. The transformation is also accompanied by the formation of platelike surface reliefs, The surface relief angles have been determined from observations (7.9 degrees +/- 0.2 degrees) and calculations based on a phenomenological analysis (7.83 degrees), The fair agreement of these values indicates that the transformation is martensitic and mainly governed by a shear mechanism.