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arXiv · 2408.10421

Itinerant A-type Antiferromagnetic Order in Co$_{0.25}$TaSe$_2$

H. Cein Mandujano·Gicela Saucedo Salas·Peter Y. Zavalij·Alicia Manjón-Sanz·Nicholas P. Butch·Efrain E. Rodriguez
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Abstract

We present the magnetic behavior and resulting transport properties of TaSe$_2$ when intercalated by magnetically active cobalt cations. Acting as the layered host, TaSe$_2$ is a transition metal dichalcogenide (TMD) that adopts the 2H-polytype. We find through our single crystal and powder diffraction studies that we can prepare the stoichiometry Co$_{0.25}$TaSe$_2$, which crystallizes in the centrosymmetric space group $P6_3/mmc$. From magnetic susceptibility and x-ray photoelectron spectroscopy measurements, we find a transition consistent with antiferromagnetic order below the temperature $T_N$ = 173 K and Co$^{2+}$ in the high-spin state. Neutron powder diffraction and specific heat measurements, however, point to a much smaller than anticipated ordered moment in this sample. From the neutron results, the magnetic structure can be described as an A-type antiferromagnet with an ordered moment size of 1.35(11) $\mu_B$ per Co cation. The direction of the moments are all long the c-axis, which is consistent with the magnetization and susceptibility studies showing this direction to be the easy axis. Interestingly, we find that a weak and subtle ferromagnetic component appears to exist along the $ab$-plane of the Co$_{0.25}$TaSe$_2$ crystals. We place the results of this work in the context of other magnetic-ion intercalated TMDs, especially those of Ta and Nb.

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H. Cein Mandujano, Gicela Saucedo Salas, Peter Y. Zavalij, Alicia Manjón-Sanz, Nicholas P. Butch, Efrain E. Rodriguez. 2024-08-19. Itinerant A-type Antiferromagnetic Order in Co$_{0.25}$TaSe$_2$. https://doi.org/10.1103/physrevb.110.144420

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