Surface Relief Induced by Martensitic Transformation in Phosphorus‐Bearing Dicalcium Silicate

Abstract

Crystals of (Ca1.955□0.045)(Si0.91P0.09)O4, where □ denotes a vacancy, have been prepared and examined by XRD, optical microscopy, SEM, and AFM. At 20°C, the crystals are composed of 38%α′L and 62%β phases. Upon cooling to −185°C, the α′L‐ to β‐phase transformation occurs, which increases the β‐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°± 0.2°) and calculations based on a phenomenological analysis (7.84°). The fair agreement of these values indicates that the transformation is martensitic and mainly governed by a shear mechanism.