Growth mechanisms of surface crystallized diopside

• Published in: CrystEngComm Vol. 15; no. 32; pp. 6381 - 6388
• Main Authors: Otto, Katrin, Wisniewski, Wolfgang, Rssel, Christian
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: Calcium magnesium silicates; Crystal growth; Crystallization; Diopside; Electron back scatter diffraction; Glass; Orientation; Scanning electron microscopy
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/c3ce40796a

The two glasses A and B of similar composition are melted and annealed at 870 C for up to 20 h to initiate the surface crystallization of diopside. Phase and orientation analyses are performed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Both glasses show two discernible layers of crystal growth into the bulk: while multiple phases occur in glass A only diopside is detected in the adapted glass B. The most part of crystal growth in layer 1 is subject to an orientation change of 90. In the adapted glass B, the predominant c -axes orientations of layer 1 and 2 are orthogonal to each other. Sample deformation and specific crack patterns near the surface are described and explained by occurring tensions. The growth of surface crystallized diopside into the bulk occurs by two different mechanisms: a primary layer of large growth and a fine grained secondary layer of different texture.