The Kondo Effect in Ce x LaLuScY (x = 0.05-1.0) High-Entropy Alloys

Julia Petrović; Stanislav Vrtnik; Andreja Jelen; Primož Koželj; Jože Luzar; Peter Mihor; Qiang Hu; Magdalena Wencka; Bojan Ambrožič; Anton Meden; Goran Dražić; Sheng Guo; Janez Dolinšek

doi:10.3390/ma16247575

The Kondo Effect in Ce _x LaLuScY (x = 0.05-1.0) High-Entropy Alloys

Materials (Basel). 2023 Dec 9;16(24):7575. doi: 10.3390/ma16247575.

Authors

Julia Petrović¹, Stanislav Vrtnik¹, Andreja Jelen¹, Primož Koželj^{1

2}, Jože Luzar¹, Peter Mihor¹, Qiang Hu³, Magdalena Wencka^{1

4}, Bojan Ambrožič⁵, Anton Meden⁶, Goran Dražić⁷, Sheng Guo⁸, Janez Dolinšek^{1

2}

Affiliations

¹ Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
² Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia.
³ Institute of Applied Physics, Jiangxi Academy of Sciences, Changdong Road 7777, Nanchang 330096, China.
⁴ Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland.
⁵ Center of Excellence in Nanoscience and Nanotechnology, Jamova 39, SI-1000 Ljubljana, Slovenia.
⁶ Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.
⁷ Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia.
⁸ Industrial and Materials Science, Chalmers University of Technology, 41296 Göteborg, Sweden.

Abstract

In the search for electronic phenomena in high-entropy alloys (HEAs) that go beyond the independent-electron description, we have synthesized a series of hexagonal rare earth (RE)-based HEAs: Ce_xLaLuScY (x = 0.05-1.0). The measurements of electrical resistivity, magnetic susceptibility and specific heat have shown that the Ce_xLaLuScY HEAs exhibit the Kondo effect, which is of a single impurity type in the entire range of employed Ce concentrations despite the alloys being classified as dense (concentrated) Kondo systems. A comparison to other known dense Kondo systems has revealed that the Kondo effect in the Ce_xLaLuScY HEAs behaves quite differently from the chemically ordered Kondo lattices but quite similar to the RE-containing magnetic metallic glasses and randomly chemically disordered Kondo lattices of the chemical formula RE1_xRE2_1-xM (with RE1 being magnetic and RE2 being nonmagnetic). The main reason for the similarity between HEAs and the metallic glasses and chemically disordered Kondo lattices appears to be the absence of a periodic 4f sublattice in these systems, which prevents the formation of a coherent state between the 4f-scattering sites in the T→ 0 limit. The crystal-glass duality of HEAs does not bring conceptually new features to the Kondo effect that would not be already present in other disordered dense Kondo systems. This study broadens the classification of HEAs to correlated electron systems.

Keywords: Kondo effect; high-entropy alloys; structure and microstructure.

Abstract

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