Al 27 NMR local study of the Al0.5TiZrPdCuNi alloy in high-entropy alloy and metallic glass forms
Artikel i vetenskaplig tidskrift, 2022

We report a Al27 nuclear magnetic resonance (NMR) local spectroscopic study of the NMR lineshape and Knight shift of a six-component Al0.5TiZrPdCuNi metallic alloy that can be prepared either as a crystalline high-entropy alloy (HEA) or as an amorphous metallic glass (MG) at the same chemical composition. For both structural modifications of the material (HEA and MG), we have determined the distribution of electric-field-gradient (EFG) tensors and the local electronic density of states (DOS) g(ϵF) at the Fermi level at the position of Al27 nuclei. A theoretical I=52 quadrupole-perturbed NMR spectrum, pertinent to both cubic HEAs and amorphous MGs, has been derived using the Gaussian isotropic model of the EFG tensor distribution, and excellent fits of the experimental spectra were obtained. The EFG distribution function of the MG state is about twice broader than that of the HEA state, reflecting the existence of a (distorted) crystal lattice in the latter and its absence in the former. The T2 dependence of the Knight shift indicates that the DOS is changing rapidly with energy within the Fermi level region for both structural modifications. The local DOS at the Al27 sites of the HEA sample is ∼10% larger than that of the MG state, indicating comparable degrees of disorder.

Författare

Magdalena Wencka

Institut Jožef Stefan

Polish Academy of Sciences

Matej Bobnar

Institut Jožef Stefan

Tomaž Apih

Institut Jožef Stefan

Q. Hu

Jiangxi Academy of Sciences

Sheng Guo

Chalmers, Industri- och materialvetenskap, Material och tillverkning

J. Dolinšek

Univerza V Ljubljani

Institut Jožef Stefan

Physical Review B

24699950 (ISSN) 24699969 (eISSN)

Vol. 105 17 174208

Ämneskategorier

Oorganisk kemi

Teoretisk kemi

Den kondenserade materiens fysik

DOI

10.1103/PhysRevB.105.174208

Mer information

Senast uppdaterat

2022-06-13