About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
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Grain Boundaries, Interfaces, and Surfaces: Fundamental Structure-Property-Performance Relationships
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| Presentation Title |
Influence of the Duplex CoTiO3-TiO2 Microstructure on the Nucleation and Growth of Entropy-Stabilized CoTi2O5 |
| Author(s) |
Koen J. H. Verrijt, Junyan Zhang, Jeffrey M. Rickman, Helen M. Chan |
| On-Site Speaker (Planned) |
Koen J. H. Verrijt |
| Abstract Scope |
Entropy-stabilized ceramics are only thermodynamically stable at temperatures greater than a critical temperature. One example is CoTi2O5, which can be produced via solid state reaction by heating a two-phase mixture of CoTiO3 and TiO2 above 1140 °C. Prior work has shown that the CoTi2O5 grows as pseudo single crystal domains. The duplex CoTiO3-TiO2 microstructure can be tuned beforehand by heat treatments below 1140 °C. This work focuses on understanding how the grain size and density of the duplex microstructure affects the nucleation and growth of the CoTi2O5 phase. X-ray diffraction and electron microscopy were used to study the degree of transformation and the microstructure as a function of isothermal heat-treatment time. Atomic force microscopy was further used to evaluate the interphase boundary energies of the different specimens, and hence the distribution of potent nucleation sites. |