Charge density wave behavior and order-disorder in the antiferromagnetic metallic series Eu(Ga1−xAlx)4
Year: 2018
Type: article
Abstract: The solid solution $\mathrm{Eu}{({\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Al}}_{x})}_{4}$ was grown in single crystal form to reveal a rich variety of crystallographic, magnetic, and electronic properties that differ from the isostructural end compounds ${\mathrm{EuGa}}_{4}$ and ${\mathrm{EuAl}}_{4}$, despite the similar covalent radii and electronic configurations of Ga and Al. Here we report the onset of magnetic spin reorientation and metamagnetic transitions for $x=0--1$ evidenced by magnetization and temperature-dependent specific heat measurements. ${T}_{\mathrm{N}}$ changes nonmonotonously with $x$, and it reaches a maximum around 20 K for $x=0.50$, where the $a$ lattice parameter also shows an extreme (minimum) value. Anomalies in the temperature-dependent resistivity consistent with charge density wave behavior exist only for $x=0.50$ and 1. Density functional theory calculations show increased polarization between the Ga-Al covalent bonds in the $x=0.50$ structure compared to the end compounds, such that crystallographic order and chemical pressure are proposed as the causes of the charge density wave behavior.
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, Johns Hopkins University, Canadian Light Source, Office of Science, Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, Western Economic Diversification Canada, National Research Council Canada, Division of Materials Research, Basic Energy Sciences, Lawrence Berkeley National Laboratory
Awards: G1079818582, G1143651532, G1286236842, G1286251239, G16587699, G1863003419, Synthesis and Characterization of New Zintl Phases for Thermoelectric Applications, G2271029047, G2618837358, G30714459, G3083819904, Crystal Chemistry and Properties of Zintl Phases: Towards Efficient New Thermoelectrics, G3736341148, G3967535168, G4061288673, G419881185, G42916606, G4501827968, G4900308727, Emilia Morosan Materials Synthesis Investigator Award, G498139845, G6098593353, G6250380926, G650090426, G6652958823, G7354628648, G969889393
OpenAlex ID: W2795453035