| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Non-Ideal Mixing in Entropy Stabilized Oxides |
| Author(s) |
William Rosenberg, Stuart Ness, Bhoopesha Mishra, Carlo Segre, Scott J. Mccormack |
| On-Site Speaker (Planned) |
Scott J. Mccormack |
| Abstract Scope |
There has been a lot of interest in “High” Entropy and/or entropy stabilized materials. However, there has been little studies that dig deep into the thermodynamics and quantify thermodynamic parameters like the excess mixing enthalpy and mixing volume. We measure the enthalpy of mixing between two entropy stabilized oxides (HfTiO4-ZrTiO4) to quantify the enthalpic effects in these disordered materials. These measurements are compared with the anisotropic volume of mixing. The enthalpy of mixing in HfTiO4-ZrTiO4 was found to be negative with respect to HfTiO4 and ZrTiO4 end-members. This suggests that there is local ordering when comparing the HfTiO4-ZrTiO4 solid solution to HfTiO4 and ZrTiO4 entropy stabilized end members. This non-ideal mixing was observed in the anisotropic molar volume of mixing, where the excess strain was confined predominantly to the b-direction. EXAFS data has been used to probe the local structure to determine nearest neighbor cation coordinations within the solid solution. |