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arXiv · 1804.02076

Charge density wave behavior and order-disorder in the antiferromagnetic metallic series Eu(Ga_1-xAl_x)_4

Macy Stavinoha·Joya A. Cooley·Stefan G. Minasian·Tyrel M. McQueen·Susan M. Kauzlarich·C. -L. Huang·E. Morosan
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Abstract

The solid solution Eu(Ga_1-xAl_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 EuGa_4 and 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_N changes non-monotonously 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 for x = 0.50 and 1 only. 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.

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Macy Stavinoha, Joya A. Cooley, Stefan G. Minasian, Tyrel M. McQueen, Susan M. Kauzlarich, C. -L. Huang, E. Morosan. 2018-04-05. Charge density wave behavior and order-disorder in the antiferromagnetic metallic series Eu(Ga_1-xAl_x)_4. https://doi.org/10.1103/physrevb.97.195146

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