Modulated Magnetism and Anomalous Electronic Transport in Ce3Cu4As4O2

Published

August 29, 2016

Author(s)

Jiakui K. Wang, Shan Wu, Yiming Qiu, Jose Rodriguez Rivera, Qingzhen Huang, Collin L. Broholm, E. Morosan

Abstract

The complex magnetism and transport properties of tetragonal Ce₃Cu₄As₄O₂ were examined through neutron scattering and physical properties measurements on polycrystalline samples. The lamellar structure consists of alternating layers of CeCu₄As₄ with a single square Ce lattice and Ce₂O₂ bi-layers. Peaks in the specific heat at the Neel temperature T_N = 25 K, T₂ = 16 K and T₃ = 1.9 K indicate three magnetic Phase transitions or distinct cross-over phenomena. For TN neutron diffraction indicates the development of ferromagnetic ab sheets for both Ce sites, with alternating polarization along c, and a wave vector k₁ = c^*. For T2, quasi-two-dimensional low-energy spin fluctuations with ld2 = 1⁄2a^* and polarized perpendicular to k₂are suppressed. The data are consistent with quasi-two-dimensional antiferromagnetic order in the CeCu₄As₄ polarized along the k_{2 wave vector. T}d3^ marks a spin-flop transition where the k₁ staggered magnetization switches to in-plan polarization. There are significant transport anomalies associated with the transitions, in particular a substantial reduction in resistivity for TN. At T = 100 mK the magnetic correlation length exceeds 75 A and the k₁ modulated staggered moment is 0.85 υB, which matches the 0.8 υB saturation magnetization achieved for υοH = 7 T at T = 2 K. We trace the unusual sequence of magnetic transitions to competing interactions and anisotropies in the alternating quasi-two-dimensional magnetic layers.

Citation

Physical Review B

Volume

94

Issue

6

Pub Type

Journals

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Keywords

Magnetism, Neutron Scattering, Frustration

Citation

Wang, J. , Wu, S. , Qiu, Y. , Rodriguez Rivera, J. , Huang, Q. , Broholm, C. and Morosan, E. (2016), Modulated Magnetism and Anomalous Electronic Transport in Ce₃Cu₄As₄O₂, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921570 (Accessed May 2, 2024)