About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
|
Symposium
|
Energy Materials for Sustainable Development
|
Presentation Title |
Atomic Defects and Ordering in the Spin Gapless Semiconducting Heusler Compound of Mn2CoAl and Their Impact on Transport Properties |
Author(s) |
Heng Wang, Runzi Cui, Qi An, Sarah Watzman |
On-Site Speaker (Planned) |
Heng Wang |
Abstract Scope |
Mn2CoAl is a Heusler compound which is predicted to have a Spin Gapless Semiconductor (SGS) state. This can be utilized for efficient spin injection in spin-logic devices for next generation computing. In order to secure the SGS state, we need detailed knowledge on the phase compositions and defect structures, as well as how they are affected by the system’s thermal history. In this work, Mn2CoAl with controled compositions were synthesized and the phase composition and atomic disorders were studied. Stoichiometric Mn2CoAl is not a single, thermodynamically stable phase, as revealed by SEM, even though the X-ray diffraction pattern remained largely “single phase”. Using high resolution synchrotron diffraction we could identify two slightly different structures. This is interpreted using 1) two different orderings commonly found in Heusler compounds, as well as 2) a potential spinodal decomposition process. Lastly, the implication of atomic structures on electronic and magneto-electronic transport properties are studied. |