Distinctive Electronic Characteristics and Ultra-high Thermoelectric Power Factor in Be-Fe Intermetallics
arXiv:2411.15780 · doi:10.1039/D4TA03256J
Abstract
Beryllium (Be) alloys are indispensable in cutting-edge applications due to their unique advantages. However, the scientific understanding about their structure and property is deficient, which greatly restricts their applications within a narrow field. In this work, a systematic investigation on the structure and properties of Be-Fe binary was carried out with first-principles unbiased evolutionary algorithms. Five new intermetallics unreported before, including insulating Be11Fe and Be4Fe, metallic Be3Fe, and metastable BeFe and BeFe2 were discovered, among which Be11Fe has a unique clathrate structure and is an electride. Surprisingly, we found that Fe unexpectedly acts as an anion in all known Be-Fe intermetallics, and its valence state can even reach -5, leading to the complete filling of its 3d orbitals. Most of these compounds exhibiting a gap or pseudogap at the Fermi level. Specifically, the band gap is determined as 0.22 eV and 0.85 eV for Be11Fe and Be4Fe at the level of single-shot GW, respectively. This is the first report of insulating phases in Be-based intermetallics. We also discovered that Be11Fe exhibits an impressive thermoelectric power factor of 178 at room temperature, to our best knowledge, the highest among known semiconductors under ambient conditions, indicating its potential for waste heat harvesting and active cooling. These findings will deepen our understanding of Be-based and Fe-based compounds, and expand the application fields of Be-based alloys to a brand-new realm.
29 pages, 6 figures, with Supplementary Information
References in corpus (12)
- The James Webb Space Telescope
- BoltzTraP2, a program for interpolating band structures and calculating semi-classical transport coefficients
- EPW: Electron-phonon coupling, transport and superconducting properties using maximally localized Wannier functions
- p-type Bi2Se3 for topological insulator and low temperature thermoelectric applications
- Phonon-glass electron-crystal thermoelectric clathrates: Experiments and theory
- Xenon Reacts with Iron at the Conditions of the Earth's Core
- Electronegativity and chemical hardness of the elements under pressure
- Interplay of anionic quasi-atom and interstitial point defects in electrides: abnormal interstice occupation and colossal charge state of point defects in dense FCC-lithium
- Prediction of anomalous LA-TA splitting in electrides
- Crystal structure, thermodynamics, magnetics and disorder properties of Be-Fe-Al intermetallics
- Compression and phase diagram of lithium hydrides at elevated pressures and temperatures by first-principles calculations
- Universal Metallic Surface States in Electride