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Updated: May 4, 2026

Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals
Published on: February 9, 2017
Viscous fingering and dendritic growth of surface crystallized Sr2TiSi2O8 fresnoite
Wolfgang Wisniewski1, Marek Patschger1, Christian Rüssel1
1Otto-Schott-Institut, Jena University, Fraunhoferstr. 6, 07743 Jena, Germany.
Abstract:
During the quenching of a melt with the composition 2SrO·TiO2·2.75SiO2, cubic SrTiO3- and tetragonal Sr2TiSi2O8-crystals are formed at the surface. Subsequent crystal growth leads to dendritic fresnoite structures which become increasingly finer until the mechanism changes to viscous fingering during further cooling. In the final stages of this initial growth step, the crystal orientations of these dendrites systematically change. Due to a complete absence of bulk nucleation in this system, crystal growth is resumed upon reheating to 970°C and fractal growth with the c-axis tilted by about 45° from the main growth direction is observed. The results are interpreted to confirm the link between viscous fingering and dendritic growth in the case of a true crystallization process.
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