Monika Kušter (Avtor), Anton Meden (Avtor), Boštjan Markoli (Avtor), Zoran Samardžija (Avtor), Maja Vončina (Avtor), Pascal Boulet (Avtor), Émilie Gaudry (Avtor), Jean-Marie Dubois (Avtor), Sašo Šturm (Avtor)

Povzetek

This study focused on the crystal and electronic structures of a newly discovered phase in the Al-Cr-Sc system. The latter two species do not mix in a binary alloy, but can be alloyed with aluminium in the vicinity of the Al$_{2−x}$Cr$_x$Sc composition, where 0.3 < x < 0.5. After preparation of the pure constituents via arc melting, high-temperature annealing at 990 °C for 240 h was required to achieve full mixing of the elements. A detailed characterisation of the crystal structure, alloy microstructure and stability was obtained using single-crystal X-ray diffraction (SCXRD) and powder X-ray diffraction (PXRD), in addition to transmission electron microscopy (TEM), especially in highangle annular dark-field scanning transmission electron microscopy (HAADF-STEM) mode, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDXS) and differential scanning calorimetry (DSC) measurements. The crystal structure was refined to a hexagonal unit cell of the MgZn$_2$ type, space group no. 194, P6$_3$/mmc, which belongs to the Laves phases family. Special attention was paid to the occupancy of the crystallographic sites that were filled by both Cr and Al atoms. First-principles calculations based on the density functional theory (DFT) were performed to investigate the electronic structure of this ternary phase. The total density of states (DOS) exhibited a pronounced sp character, where a shallow pseudo-gap was visible 0.5 eV below the Fermi energy that brought a small but definite contribution to the thermodynamic stability of the compound.

Ključne besede

Al-Cr-Sc system;Laves phase;crystal structure refinement;HAADF-STEM;

Podatki

Jezik: Angleški jezik
Leto izida:
Tipologija: 1.01 - Izvirni znanstveni članek
Organizacija: UL NTF - Naravoslovnotehniška fakulteta
UDK: 669
COBISS: 88540675 Povezava se bo odprla v novem oknu
ISSN: 2073-4352
Št. ogledov: 98
Št. prenosov: 45
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Vrsta dela (COBISS): Članek v reviji
Strani: 1535-1-1535-18
Letnik: ǂVol. ǂ11
Zvezek: ǂiss. ǂ12
Čas izdaje: 2021
DOI: 10.3390/cryst11121535
ID: 15297835