About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
High-Entropy Materials: Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond VI
|
| Presentation Title |
Entropy Stabilized (Co,Cu,Ni,Mg,Zn)O: A Comprehensive Study of Cu-compositional Variation on Structure and Electrical Behavior |
| Author(s) |
Arturo A. Meza, Aneeta Manjari Padhan, Alexander D. Dupuy, Julie M. Schoenung |
| On-Site Speaker (Planned) |
Aneeta Manjari Padhan |
| Abstract Scope |
We demonstrate the effect of tunable phase-state and microstructure on the electrical behavior of entropy-stabilized (CoNiMgZn)yCuxO; x =0.1 to 0.3, y =(1-x)/4. We vary Cu content (x) and post-consolidation heat-treatment temperature to investigate the temperature-dependent reversibility between single-phase (rock-salt) and multi-phase (includes Cu-rich tenorite and Co-rich spinel secondary phases) states. Secondary-phase formation increases with increasing x. The multi-phase electrical behavior differs strikingly from the single-phase behavior. Peak conductivities ~10-8, 10-7, 10-5 S.cm-1 and dielectric constants ~102, 103, 104 are observed for x = 0.1, 0.2, 0.3 at their maximum secondary-phase concentration. Single-phase values are ~10-10 S.cm-1 and ~101, respectively. The high conductivity is attributable to a percolation network of the Cu-rich tenorite secondary phase, which is highly conductive by nature and segregates to the grain boundaries. High dielectric constant originates from the space-charge effect at the primary-secondary phase interfaces within the grain interior. These two mechanisms are discussed in detail. |