Publication details
What is the true ground state of intermetallic compound Fe3Al?
| Authors | |
|---|---|
| Year of publication | 2024 |
| Type | Article in Periodical |
| Magazine / Source | SOLID STATE SCIENCES |
| MU Faculty or unit | |
| Citation | |
| web | https://www.sciencedirect.com/science/article/pii/S1293255824002747?via%3Dihub |
| Doi | http://dx.doi.org/10.1016/j.solidstatesciences.2024.107709 |
| Keywords | 2-structure; Ab-initio electronic structure calculations; Exchange correlation energy; Generalized gradient approximations; Ground-state structures; High-energy barriers |
| Description | We discuss recent doubts about the true ground-state (GS) structure of the intermetallic compound Fe3Al. It seems that it should be the D0(3) structure (observed experimentally), but there are some considerations that, perhaps, D0(3) might be a high-temperature (>400 K) structure and the GS at 0 K might be the L1(2) structure because there might be a high energy barrier between both structures and, when the temperature is lowered, the system is not able to transform into the (perhaps) lower-energy L1(2) structure. To elucidate this problem, we re-interpret our recent extended ab initio electronic structure calculations for Fe3Al performed with the help of the VASP code and using various exchange-correlation energies within the generalized gradient approximation (GGA). Regrettably, some calculations provide the L1(2) and some of them D0(3) as the GS structure. To resolve this question, we performed further calculations testing 9 frequently applied metaGGAs, such as TPSS, revTPSS, M06-L, SCAN(-L), rSCAN(-L) and r(2)SCAN(-L) representing a higher rung of the Jacob's ladder. It turns out that also here some meta-GGAs lead to L1(2) and some others to D0(3) GS structure and, again, we cannot decide. In this way, the present results represent the very first step on the way to understand the energetics of the Fe3Al compound and its ground state. We hope they may motivate future theoretical and experimental work in this direction. |