Magnetic Structures of Rare Earth Intermetallic Compounds RCuAs2 (R = Pr, Nd, Tb, Dy, Ho, and Yb)

Published: July 14, 2017

Author(s)

Yang Zhao, Jeffrey W. Lynn, Gohil S. Thakur, Zeba Haque, L. C. Gupta, A. K. Ganguli

Abstract

Neutron scattering studies have been carried out on polycrystalline samples of a series of rare earth compounds RCuAs2 (R=Pr, Nd, Dy, Tb, Ho and Yb) as a function of temperature to determine the magnetic structures and the order parameters. These compounds crystallize in the ZrCuSi2 type structure, which is similar to that of the RFeAsO (space group P4/nmm) class of iron-based superconductors, PrCuAs2 develops a commensurate magnetic order with K = (0, 0, 0.5) below TN = 6.5(2) K. with the ordered moments pointing along the c-axis. The irreproducible representation analysis shows either a Γ12 or Γ13 representation. NdCuAs2 and DyCuAs2 order below TN = 3.54(5) K and TN = 10.1(2) K, respectively, with the same ordering wave vector (with a Γ29 or Γ210 representation) but the moments lying in the a-b plane. TbCuAs2 and HoCuAs2 exhibit incommensurate magnetic structures below TN = 9.44(7) and 4.41(2) K. respectively. YbCuAs2 does not show any magnetic Bragg peaks at 1.5 K, while the susceptibility measurements indicate an antiferromagnetic-like transition at 4 K, suggesting that either the ordering is not long range in nature or the ordered moment is below the sensitivity limit of {approximately equal} 0.2 υB.
Citation: Journal of Physics and Chemistry of Solids
Volume: 111
Pub Type: Journals

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Keywords

Antiferromagnetism
Created July 14, 2017, Updated September 08, 2017