Interplay of sample composition and anomalous Hall effect in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Co</mml:mi><mml:mi>x</mml:mi></mml:msub><mml:mi>Nb</mml:mi><mml:msub><mml:mi mathvariant="normal">S</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:mrow></mml:math>
Sebastian Mangelsen, Philipp Zimmer, Christian Näther, S. Mankovsky, S. Polesya, H. Ebert, Wolfgang Bensch
Abstract
Herein we present a study on the interplay of chemical composition with respect to $x$ in antiferromagnetic ${\mathrm{Co}}_{x}\mathrm{Nb}{\mathrm{S}}_{2}$ and the anomalous Hall effect (AHE) in the magnetically ordered state. The AHE diminishes virtually completely in samples with exceeding Co content compared to the idealized composition of $x=1/3$. For stoichiometric samples the effect is weak but shows a sign reversal just below the magnetic ordering temperature. With increasing deficiency, the magnitude of the AHE compared to the ordinary Hall effect increases and additionally an exchange-biaslike effect can be observed. The results reveal the chemical composition of the samples as tuning parameter for the AHE in ${\mathrm{Co}}_{x}\mathrm{Nb}{\mathrm{S}}_{2}$. Accompanying first-principles calculations demonstrate that the electronic band structure is only slightly affected by disorder and deficiency of Co, but an impact on the magnetic exchange coupling can be inferred. The results are interesting for the research on $3d$-metal inserted transition-metal dichalcogenides and in a broader context for the understanding and design of antiferromagnet-based spintronic materials.