TY - JOUR A1 - Waurischk, Tina A1 - Thieme, C. A1 - Rüssel, C. T1 - Crystal growth velocities of a highly anisotropic phase obtained via surface and volume crystallization of barium–strontium–zinc silicate glasses T2 - Journal of Materials Science N2 - In the past few years, a new phase, Ba0.5Sr0.5Zn2Si2O7 with negative thermal expansion has been described in the literature. Some excess of SiO2 is necessary to produce glasses from which the Ba0.5Sr0.5Zn2Si2O7 phase can be crystallized. Unfortunately, in such glasses usually surface crystallization occurs; however, the addition of nucleating agents such as trace quantities of platinum or relatively high quantities of ZrO2 is necessary to achieve bulk nucleation. These additional components also affect the crystal growth velocity, which furthermore is different for crystal growth from the surface and in the bulk. In this paper, three different chemical compositions containing different ZrO2 concentrations, where one composition additionally contains 100 ppm platinum, are studied with respect to their crystallization behaviour. Although the compositions do not differ much, the crystallization behaviour and also the Crystal growth velocities are surprisingly different. PB - Springer KW - Glass ceramic KW - Crystal growth velocity KW - Low expansion PY - 2020 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/50853 AN - OPUS4-50853 SN - 0022-2461 VL - 55 SP - 10364 EP - 10374 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany